Wikipedia:Reference desk/Archives/Computing/2011 March 22

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March 22

HP Pavilion Laptop DV1000 (An old but brill laptop that HP made but did not seem to produce for long!!!)

Hi All,

Is there anyone who might have some idea what driver might work to get the internal microphone running again on this laptop.

It orignally came pre-loaded with Windows XP and said it was "upgradable" to Win Vista, which was upgraded and ran the internal microphone fine.

Subsequently I have upgraded to Windows 7 Home Premuim (genuine version) and since then the internal mic won't work, very annoying.

Silly thing is everything else works fantastic with Win 7, even though the laptop is quite slow processor wise, it runs just fine........

Note: the built in speakers have always worked with every version of Windows from the outset, but not this internal mic (from Windows 7).....I cannot understand why this Win version won't somehow run that internal mic? What is even stranger is that an external mic, plugged in to the input socket works fine, (which only cost $20), but it is annoyinfg me why some how I cannot get the right driver to make that internal mic work!!

Needless to say HP don't produce a Win 7 driver for this machine........typical HP!!

Any help would be very welcome!!!

Thanks whoever!!!! —Preceding unsigned comment added by 116.212.193.250 (talk) 03:10, 22 March 2011 (UTC)

Try this. [1] ---— Gadget850 (Ed) ^talk 17:32, 22 March 2011 (UTC)

Windows XP

WHAT IS THE FULL FORM OF WINDOWS XP? —Preceding unsigned comment added by 180.215.123.1 (talk) 08:47, 22 March 2011 (UTC)

I'm not quite sure what you mean, but if you want to know what the "XP" stands for it is "experience". (Writing in all CAPS is considered poor netiquette by the way, as it makes it harder to read) SmartSE (talk) 11:34, 22 March 2011 (UTC)

I don't think caps are harder to read, but they are "like shouting". StuRat (talk) 15:17, 22 March 2011 (UTC)

Our article, All caps, notes that indeed ALL CAPS IS HARDER TO READ. Comet Tuttle (talk) 16:34, 22 March 2011 (UTC)

Windows XP Professional includes a number of features that other versions of Windows XP (like Windows XP Home, and Windows XP Starter) do not have. The "Windows XP Media Center Edition" is the same as Windows XP Professional with Windows Media Center included. I hope this answers your question — if it does not, could you ask with a little more detail about the exact information you are seeking? Comet Tuttle (talk) 16:34, 22 March 2011 (UTC)

Why do we have to have a discussion about netiquette and the causes and effects of ALL CAPS TYPING... can't we just assume its a n00b who doesn't know any better and let it slip? — Preceding unsigned comment added by Roberto75780 (talk • contribs) 05:50, 23 March 2011 (UTC)

That the poster doesn't know any better about all caps is precisely why it is a good idea to point it out to them. 82.32.186.24 (talk) 10:50, 26 March 2011 (UTC)

Excel questions

1) How to change a number written in words (e.g. seven hundred and seventy seven) to a numerical (e.g. 777) and vice versa in Microsoft excel 2007.

2) How to change a numerical date (e.g. 16-02-2011) to a date written in words (e.g. fifth of Feb two thousand eleven) and vice versa in Microsoft excel 2007.

3) how to create a PDF document offline. — Preceding unsigned comment added by Gopalmishra77 (talk • contribs) 09:04, 22 March 2011 (UTC)

To Q2, highlight the cells, right click and then choose "format cells" and you can change the format of dates. It doesn't seem to work for written numbers as far as I can tell. To Q3 - you should be able to use file > save as and choose .pdf as the format. That certainly works for me in recent versions of MS office. If you can't do that, search for the file format you wish to convert and pdf converter, so for example use ".doc .pdf converter". SmartSE (talk) 11:40, 22 March 2011 (UTC)

Answer to Q3 - download PrimoPDF and use the Excel plugin. Rocketshiporion♫ 07:37, 27 March 2011 (UTC)

How can I find out what programs are accessing the internet?

Is there anyway to see what programs are receiving data from the internet? I'd like to know as I'm often restricted to accessing the internet through mobile networks and something eats up megabytes of data in minutes. I've already disabled updates for windows, antivirus, open office, itunes etc. and am a bit stuck as to what else could be using it. Anyone got any ideas what it could be? Thanks in advance SmartSE (talk) 11:32, 22 March 2011 (UTC)

Is this what you are looking for? General Rommel (talk) 11:38, 22 March 2011 (UTC)

I should also add that you need to scroll down quite a bit till you dee the download link General Rommel (talk) 11:39, 22 March 2011 (UTC)

Yes, that's awesome, especially as it is only 63kb! Sorry for being lazy and not reading the readme file, but is there any way to see the volume of traffic passing through each port? SmartSE (talk) 11:45, 22 March 2011 (UTC)

Or try Microsoft's own TCPview. -- Finlay McWalter ☻ Talk 11:52, 22 March 2011 (UTC)

I tried that one, and it says "netbios-ns" is both sending and receiving data over the Internet. What's it doing ? StuRat (talk) 15:15, 22 March 2011 (UTC)

netbios-ns is the Netbios name service (it's a bit like DNS), probably on port 137. You probably want to firewall that off, at least for the internet proper. -- Finlay McWalter ☻ Talk 17:06, 22 March 2011 (UTC)

You can also use the netstat command that comes with Windows.[2] ---— Gadget850 (Ed) ^talk 17:29, 22 March 2011 (UTC)

As Gadget says, netstat is the easiest way to go. At the command prompt (Run > "cmd"), try netstat -b (if you're in vist/7 it'll require you to run this as an administrator). Alternatively you can use netstat -o which will tell you the PID (and you can use task manager to match the PID to the process name). Shadowjams (talk) 20:00, 22 March 2011 (UTC)

Exiting Firefox

Usually when I exit Firefox on my system here at work (Ubuntu 10.04/Firefox 3.6.15), it exits quite OK. If I have more than one tab I am asked if I want to exit all tabs. However, Firefox sometimes asks if I want to save my tabs for next time. I can tick the box to not be asked about saving, but I'm curious about the strategy it uses to decide whether to ask if I want to save, or to ask if I want to exit all tabs. Astronaut (talk) 12:03, 22 March 2011 (UTC)

Do the tick boxes at Tools > Options > Tabs answer your question?--Shantavira|^{feed me} 12:42, 22 March 2011 (UTC)

No they don't. All I have (on Edit->Preferences->Tabs by the way) that is relevant is the option to "Warn me when closing multiple tabs". Nothing about when to ask about saving tabs. Astronaut (talk) 12:48, 22 March 2011 (UTC)

There does seem to be "something wonky" about how it exits. In my case, on Windows XP, it always asks if I want to save the tabs, but never does, no matter what I pick. On the same computer, Opera does save the tabs. Also, on an earlier Windows 98 machine, Firefox didn't seem to even ask if it should save them. It never did, if I closed Firefox normally. On the other hand, if the computer went down, then it apparently did try to save the tabs, and asked if I wanted to restore them, the next time I started. StuRat (talk) 14:55, 22 March 2011 (UTC)

Different in Firefox 4, isn't it? ¦ Reisio (talk) 02:19, 23 March 2011 (UTC)

I've no idea. I'm certainly not going to install any 'beta' or 'release candidate' version to find out and would like a longer track record than yesterday's official release. Astronaut (talk) 11:11, 23 March 2011 (UTC)

GNU Octave - parfor Equivalent

  Does Octave have an eqivalent to MATLAB's parfor function? Typing help parfor at the command prompt results in an error. Thanks. Rocketshiporion♫ 13:54, 22 March 2011 (UTC)

Octave unfortunately has limited support for multi-core or multi-machine parallelism. Octave-Forge has a multicore package but I have not had luck with it. If you need parallel computing support, MATLAB has that capability. This single feature may be the best incentive, currently, to purchase a commercial MATLAB license, as the open-source community seems to be lagging behind MATLAB's technology in this area. Nimur (talk) 16:42, 22 March 2011 (UTC)

Thanks anyway, Nimur. But I think I'll wait for the FOSS community to catch up with MATLAB. Just the base MATLAB R2010b package is priced at almost S$6K, and each individual toolbox is priced at over S$2K! And even then the Parallel Computing Toolbox allows only up to eight workers - still can't use all the twelve cores on my workstation. Rocketshiporion♫ 08:18, 24 March 2011 (UTC)

Conditional CSS

Is there a way to create a CSS rule so alphabets are italic and other characters are roman? It would be nice for doing mathematical expressions, such as:

y = 2x + 1

Is it possible? -- Toytoy (talk) 14:08, 22 March 2011 (UTC)

I don't believe CSS has any way of affecting content without markup. You'll have to process it to look like:

<span class="char">y</span> = 2<span class="char">x</span> + 1

and then do

.char { font-style: italic; }

--Sean 14:37, 22 March 2011 (UTC)

You can put the whole thing in a math style like <span class='math'>y=2x+1<span>. Then, you can use CSS to do overall styling in the math class. For character-specific stuff, you have to use JavaScript. First, get all content by class. Then, parse the strings. It won't be very easy as you'll have to climb around the DOM tree to get actual content. Then, you have to put each character into an italic class. Overall, it is a lot of work, but then it will save you a lot of work typing <i> over and over. -- kainaw™ 14:43, 22 March 2011 (UTC)

Well, it's not that much work... --Mr.98 (talk) 14:59, 22 March 2011 (UTC)

(ec) With CSS alone, no. But with Javascript, yes. Imagine that every equation was in paragraph element with the classname of "equation". The Javascript would search through all paragraphs with that classname, determine all a-z characters, and put them in italic tags, automatically. Here's a very quick and dirty example:

Extended content

<html> <head> <script type="text/javascript"> //process_equations function needs to be set to run "onload" in the body element function process_equations() { //create a variable 'p', that is an array of all paragraph (<p>) elements in the page var p = document.getElementsByTagName('p'); //iterate over all elements in the array p for(i=0; i<p.length; i++) { //if the class of this particular item in the p array is "equation" if(p[i].className=="equation") { //set up two variables -- one the text we are going to process, one a text buffer we are going to output text_in = p[i].innerHTML; text_out = ""; //iterate over every character in the input text for(x=0; x<text_in.length; x++) { //if the character (made uppercase for comparative purposes) is both >="A" and <="Z", then... if((text_in.charAt(x).toUpperCase() >= "A") && (text_in.charAt(x).toUpperCase() <= "Z")) { //the character is put into italics and put into the output buffer text_out = text_out + "<i>"+text_in.charAt(x)+"<\/i>"; } else { //otherwise, just add the character to the output buffer without changing it text_out = text_out + text_in.charAt(x); } } //finally, replace the paragraph data with the output buffer p[i].innerHTML = text_out; } } } </script> </head> <body onload="process_equations()"> <p>Here is an equation:</p> <p class="equation"> y = 2x + 1 </p> </body> </html>

The code above should be pretty straightforward to make sense of-- it iterates over all paragraphs, checks their classnames, then iterates over each character in the correct paragraphs, determines if it is a letter from A to Z (this is the ugliest part above), and if so, puts italic tags around it. --Mr.98 (talk) 14:58, 22 March 2011 (UTC)

That code assumes that there is no html inside the equation area, which I expect will not always be true. You don't want to turn something like <b> into <<i>b<\i>>. That is why I noted that you'd have to climb the dom tree, not simply parse the inner html. -- kainaw™ 16:36, 22 March 2011 (UTC)

True enough. It assumes very simple considerations — you'd have to modify it to meet your needs. But it would not be hard to make it ignore HTML tags within the inner HTML -- just a small addition of a flag that checks if we are in an HTML tag:

Extended content

<html> <head> <script type="text/javascript"> //process_equations function needs to be set to run "onload" in the body element function process_equations() { //create a flag that tells us if we are "in" an HTML tag var inTag = false; //create a variable 'p', that is an array of all paragraph (<p>) elements in the page var p = document.getElementsByTagName('p'); //iterate over all elements in the array p for(i=0; i<p.length; i++) { inTag = false; //reset this, just in case some tags were malformed previously //if the class of this particular item in the p array is "equation" if(p[i].className=="equation") { //set up two variables -- one the text we are going to process, one a text buffer we are going to output text_in = p[i].innerHTML; text_out = ""; //iterate over every character in the input text for(x=0; x<text_in.length; x++) { //first we check if this is the beginning or end of an HTML tag if(text_in.charAt(x) == "<") { //if at the beginning of a tag, mark "inTag" as true inTag = true; text_out = text_out + text_in.charAt(x); } else if(text_in.charAt(x) == ">") { //if at the end, mark as false inTag = false; text_out = text_out + text_in.charAt(x); } else { //if we are not in an HTML tag then check it... if(!inTag) { //if the character (made uppercase for comparative purposes) is both >="A" and <="Z", then... if((text_in.charAt(x).toUpperCase() >= "A") && (text_in.charAt(x).toUpperCase() <= "Z")) { //the character is put into italics and put into the output buffer text_out = text_out + "<i>"+text_in.charAt(x)+"<\/i>"; } else { //otherwise, just add the character to the output buffer without changing it text_out = text_out + text_in.charAt(x); } //if we are in an HTML tag, then just spit it out } else { text_out = text_out + text_in.charAt(x); } } } //finally, replace the paragraph data with the output buffer p[i].innerHTML = text_out; } } } </script> </head> <body onload="process_equations()"> <p>Here is an equation:</p> <p class="equation"> y = 2<b>x</b> + 1 </p> </body> </html>

Every text parsing takes assumptions about the form of the text into account. This is just meant to show that it wouldn't be very hard to set up a basic one, one that could be modified as one saw fit. --Mr.98 (talk) 21:26, 22 March 2011 (UTC)

CSS targets which content it affects with selectors. Selectors target a whole element (or a whole subtree of elements), not specific words or letters (the only exception that I can think of is the oddball :first-letter pseudo-element selector, which doesn't help you). There isn't a (sane, at least) way of selecting for the nth character of an element, or for selecting characters or words based on their content. In general CSS isn't really very expressive, and in many cases is no substitute for a server-side macro language or client-side javascript. -- Finlay McWalter ☻ Talk 15:02, 22 March 2011 (UTC)

http://reisio.com/temp/toy/ Unfortunately such an approach is purely stylistic, giving no special meaning, which is what HTML and markup in general is kind of about. ¦ Reisio (talk) 02:34, 23 March 2011 (UTC)

In case it is not clear from the markup, all Reisio has done here is made a font where all letters are italic by default. --Mr.98 (talk) 12:12, 23 March 2011 (UTC)

(which can be applied selectively via CSS ¦ Reisio (talk) 21:55, 23 March 2011 (UTC))

'Amazon Online Reader' does not work in my Firefox 3.6.15

Does anyone know why this might be? Using WinXP SP3. Thanks 92.15.6.157 (talk) 14:20, 22 March 2011 (UTC)

What happens when you try ? StuRat (talk) 14:47, 22 March 2011 (UTC)

I get a message on the page in yellow saying "Your web browser does not support this feature. Please visit our Frequently Asked Questions for a list of compatible web browsers that support the Amazon Online Reader." 92.15.23.133 (talk) 18:34, 22 March 2011 (UTC)

And is Firefox 3.6.15 in that list ? StuRat (talk) 18:53, 22 March 2011 (UTC)

After following the link given, I cannot see any list of web browsers, and the word Firefox is not on the page. 92.15.10.228 (talk) 21:19, 22 March 2011 (UTC)

Well, do they have a support staff (phone or IM or e-mail) ? You could ask them. If not, all I can suggest is trying different browsers until you find one that works. StuRat (talk) 16:05, 23 March 2011 (UTC)

It did use to work OK with Firefox, but then it stopped working. It may be the one or two Firefox upgrades I've done since then, or perhaps its a firefox app that I've downloaded. 92.24.188.210 (talk) 20:20, 24 March 2011 (UTC)

MSI CR410 laptop

Economic Times has reported that MSI CR410 laptop with all std features Wi-fi,bluetooth,webcam etc is less than INR 18,000//. Has anyone used it and is it worth what it says? Available only on online order form. —Preceding unsigned comment added by 59.92.77.228 (talk) 14:21, 22 March 2011 (UTC)

To others reading this question, "INR 18,000//" is 18,000 Indian rupees. At current exchange rates of about 45 per USD, that's $400. I have no idea what the "//" part means, though. Perhaps that's a way of saying there are no "cents" ? StuRat (talk) 14:52, 22 March 2011 (UTC)

Video Joining Software

Hi, I am looking for a video joining software, in order to join two separate video files. But I need a special feature. The videos that I wish to join are from a continuous event. I guess it was split into 2 files in order to reduce the file size. But the ending part of first video (maybe 4-5 seconds) is also repeated in the starting of the second file.

So, the requirement is for a software which while joining the files, also lets the user adjust how much time to overlap/clip.

Can anyone help me with providing some lead to such a software. A free/open source software would be preferable.

Thanks. — Preceding unsigned comment added by Kanwar rajan (talk • contribs) 15:54, 22 March 2011 (UTC)

Avidemux can do this 82.43.90.38 (talk) 16:04, 22 March 2011 (UTC)

(ec) The Windows Movie Maker software that came pre-installed on my Vista laptop can do this. It is a simple matter to eliminate the time overlap. Astronaut (talk) 16:05, 22 March 2011 (UTC)

Thanks a lot!! I will give it a try. — Preceding unsigned comment added by Kanwar rajan (talk • contribs) 16:20, 22 March 2011 (UTC)

Also VirtualDub. ---— Gadget850 (Ed) ^talk 17:21, 22 March 2011 (UTC)

Problem with search engines

This problem cropped up just today. When I try to use Google, Bing or Yahoo for search, all I get is a blank page. I tried a restart and that didn't work. I've also tried using various browsers, Opera, Firefox, IE and Chrome, and none worked. Google mail and Yahoo mail work fine, however. Any thoughts? Thanks. 71.125.150.30 (talk) 16:36, 22 March 2011 (UTC)

The standard first advice here is to download an anti-malware program, like Malwarebytes's offering, and scan your system to see whether you've got a computer virus or other malware that mucks with your outbound DNS queries, or the like, to redirect you to websites that the malware wants you to see. Comet Tuttle (talk) 16:38, 22 March 2011 (UTC)

A reboot is also worth a try here. StuRat (talk) 16:39, 22 March 2011 (UTC)

I tried a reboot and that didn't work. I downloaded Malwarebytes and I'm running that now on the problematic laptop. Thanks. 71.125.150.30 (talk) 16:53, 22 March 2011 (UTC)

Malwarebytes worked. Thanks for the help. I have been running Norton, provided by my service provider and updated regularly, but it failed to pick up a total of 32 infections. Interesting. Again, thanks.71.125.150.30 (talk) 17:07, 22 March 2011 (UTC)

You're welcome. May I recommend creating an account without administrator rights and using that account habitually? It makes it more difficult for malware to infect your operating system. The only downside is that it's occasionally annoying when you have to install something, or when using old software from the early days of Windows Vista or before that works poorly with non-admin accounts. Comet Tuttle (talk) 19:44, 22 March 2011 (UTC)

Windows 7

I have an old computer with no screen, keyboard or mouse running Windows XP which I can use via remote desktop connection from my Windows 7 computer. I want to install Windows 7 on the old computer. Is there a way I can go through the install process via remote desktop connection, so that I don't have to switch the screen and keyboard over and render the other computer unusable during the install? Also, the old computer only has 1GB of RAM so is installing Windows 7 on it going to be beneficial over XP, or will it function slower than XP currently does? 82.43.90.38 (talk) 17:05, 22 March 2011 (UTC)

Here are the minimum system requirements for Windows 7: [3]. 1GB of RAM is the minimum, so I'd be a bit wary. It probably will be slower. StuRat (talk) 17:13, 22 March 2011 (UTC)

"via remote desktop connection": No. You cannot perform an in-place upgrade from XP to 7.[4] Step 1 of that page links to the Windows 7 Upgrade Advisor which will identify potential upgrade issues. ---— Gadget850 (Ed) ^talk 17:20, 22 March 2011 (UTC)

I don't understand what you mean by "in-place". 82.43.90.38 (talk) 18:39, 22 March 2011 (UTC)

You cannot load 7 over XP and maintain settings and documents. You have to format your drive and do a clean install (nuke and pave). ---— Gadget850 (Ed) ^talk 18:46, 22 March 2011 (UTC)

I don't care about preserving settings and documents. You can assume there's no OS on the computer if that makes it easier. I just want to be able to go through the Windows 7 install procedure without attaching a keyboard and screen to the computer. I thought there might be the possibility of doing that over the Remote Desktop Protocol 82.43.90.38 (talk) 19:44, 22 March 2011 (UTC)

You can't install an OS over a remote desktop connection. You can create a DVD that will install the OS without any user input, but I suspect in your case this would be more difficult than doing it by hand. (It's useful for IT professionals who have to upgrade a bunch of machines at once.) Unless you have a specific reason to install Windows 7, though, I wouldn't bother. Don't install it in the hope of making your old computer faster, since that's very unlikely to happen. -- BenRG (talk) 19:29, 22 March 2011 (UTC)

I mainly want to install Windows 7 because Windows XP has trouble to coping with thousands of files in a folder, whereas Windows 7 has been able to. I certainly don't expect Windows 7 to increase the speed to the computer, but I was concerned that it might cause a significant decrease in speed since Windows 7 is a much larger operating system. If Windows 7 will perform as well as XP on the older hardware, that's good. 82.43.90.38 (talk) 19:49, 22 March 2011 (UTC)

XP, the operating system, doesn't have any problem with large folders. If you're having a problem it's most likely with the bundled application known as Explorer, in which case you could try using one of the alternatives to Explorer instead of replacing the whole OS. Unfortunately, Explorer's file view is also used in the standard file open/save dialogs, and I don't know which of these replacements, if any, will also work in the dialogs. You could also try to fix Explorer. Your problem could be as simple as a metadata column that requires reading every file (such as "track number" or "date picture taken") or a shell extension that you installed long ago and forgot about.

I think that a base Windows 7 install will inevitably use more RAM than a base XP install; on the other hand, I think Windows 7 does have some improvements in its caching behavior, which can make things faster. Whether the speed is faster or slower overall will depend on the amount of RAM, but I don't know where the crossover is. 1 GB may not be enough. -- BenRG (talk) 23:47, 22 March 2011 (UTC)

I've tried several explorer alternatives and they're all pretty buggy, 7zip file manager has been the best but even that has some trouble. I installed no shell things, actually the XP install is itself quite recent so there's no clutter from random programs. Anyway, thank you for your help. I guess I might give Windows 7 a test, I can always install XP back onto it it's just a bit annoying. 82.43.90.38 (talk) 15:14, 23 March 2011 (UTC)

Why don't you just use the keyboard and monitor from your main computer? Have you considered moving the hard drive from one computer to the other? Taemyr (talk) 04:04, 23 March 2011 (UTC)

Because that would render my other computer unusable for over an hour. I don't understand how moving the hard drive helps, and from experience installing Windows on one computer and then moving the hard drive to another result in the system becoming unstable and BSODing because of the significant hardware change. 82.43.90.38 (talk) 15:14, 23 March 2011 (UTC)

Right. Due to the way Windows is tied to the hardware abstraction layer, you can't install to a PC and swap the drive to a completely different model. I upgraded an older Dell D600 laptop with 1GB from XP to 7— it isn't speedy, but it does seem better than XP even after a year of adding applications.

Question: What is the file system set to on your drive? NTFS, FAT32? ---— Gadget850 (Ed) ^talk 15:23, 23 March 2011 (UTC)

Never had a problem when changing HAL due to system changes personally (including from Intel to AMD and from Athlon XP to Athlon 64 IIRC). Never done it with Windows 7 but a quick search suggests it's gotten easier not harder as one would expect. You do have to know what you're doing (I believe I described the process possibly to 82 before) but if you do not really a big deal and there are plenty of guides. Nil Einne (talk) 19:16, 23 March 2011 (UTC)

Upgrading memory on my PC

I have 512 MB of memory on my PC (CPU = Celeron#Northwood-128, O/S = Windows XP SP3 (32 bit)), and, based on a discussion further up the page, it looks like I need more memory. I have 4 memory slots, with the following contents:

1) 128 MB DDR, PC2700U CL2.5 25331 C3 0322 4X0365 121033 P/N 305956-041.

2) 256 MB DDR, PC3200U CL3   30331 A1  400 MT8VDDT3264AG-40BG4 200424 BZACH3G002 S/C: 3804740072E PN: 326667-041

3) 128 MB DDR, (Exactly the same as in slot 1).

4) Vacant.

All 3 memory cards are labeled Hewlett Packard. Slots 1 and 2 are close together, as are slots 3 and 4. Slots 1 and 3 are black, and slots 2 and 4 are blue. Sorry for all the excessive info, but I don't know which numbers are trivial and which are critical. So, here are my questions:

A) Does the slot placement of the cards matter ?

B) Is it OK to mix and match cards, like I have ?

C) I'm thinking of getting an additional 256 MB DDR card, like the one now in slot 2, and placing it in slot 4. That would give me 768 GB of RAM. But could I put a 512 MB card or 1024 MB DDR card in there, instead (to give me a total of 1 or 1.5 GB) ?

D) What significance, if any, does the color of the slot (blue versus black) have ?

E) If I decided to go all out and put in the maximum RAM my PC can handle, what would that be ? Is it only limited by my 32-bit operating system ?

F) Can I use the faster DDR2 or DDR3 memory cards ? If so, can I mix and match those with my current cards ? StuRat (talk) 21:25, 22 March 2011 (UTC)

I'll answer the ones I can;

B) I've had no problems mixing different sizes of RAM cards on my computer

C) Yes

E) 32-bit operating systems can only address 4GB usually. You can't install a 64-bit operating system on 32-bit hardware

F) No, DDR2 and DDR3 cards are shaped differently and won't fit in the slots

82.43.90.38 (talk) 22:07, 22 March 2011 (UTC)

Thanks. I assume the different shape is to prevent them being plugged into the same slots, because of some underlying incompatibility ? StuRat (talk) 22:34, 22 March 2011 (UTC)

For A, B, and D, see Dual-channel architecture. If your motherboard is indeed dual channel (and the colors and paired slots make this likely), then it is recommended that matched memory modules (as your 1 and 3 are) be put into the same channel (same colors, in your case) for best performance. If you could find a memory module identical to your 256 MB one to put in slot 4, that would work well. It might be even better (depending on your budget) to buy a matched pair of, say, 512 MB units (for an additional 1 GB) and replace your current 256 MB with one of those (the other going in the empty slot), giving you 1.5 GB total RAM. Buddy431 (talk) 22:53, 22 March 2011 (UTC)

That last calc doesn't quite add up. I would then have 2(512 MB) + 2(128 MB), or 1268 MB. StuRat (talk) 01:48, 23 March 2011 (UTC)

Right you are. 1.25 GB then. I'm not sure how much of an improvement actually matching the memory gives (though it's always recommended for dual channel), so you might want to wait for someone more technically savvy to comment. Buddy431 (talk) 03:20, 23 March 2011 (UTC)

We'd need to know the exact make (I assume HP?) and model of your computer to be able to confirm what memory choices are possible, including the maximum amount supported by it as it'll vary per computer. It's also probably worth going to the Crucial website because they have a very good memory scanner which will show you what your options are including the maximum amount of RAM you can put in it etc. I only know about their UK pricing, but it's very reasonable and we purchase all our work RAM from them because of this and the compatibiliy checker. Unfortunatly DDR 1 RAM isn't made anymore so it's likely to be expensive... :(  ZX81  ^talk 22:46, 22 March 2011 (UTC)

This is a Franken-model, meaning it's assembled from the bodies of other dead computers, so the "model" may not have much meaning. Do you need to know the motherboard ? If DDR 1 GB isn't made any more, could I get some other combo more cheaply, like two 512 MB cards ? StuRat (talk) 23:03, 22 March 2011 (UTC)

Looking at sites that sell memory, I now have even more questions:

G) 184 pin DIMM versus 200 pin SODMM ? Do I need to pull the cards back out and start counting ?

H) What is ECC and ECC Registered, and do I care if I get that ?

I) DDR memory seems to come in speed of 266, 333, and 400 MHz. Does this make much difference ? If I mix and match speeds, is the result the lowest speed for everything ? StuRat (talk) 23:10, 22 March 2011 (UTC)

What matters is the motherboard. It may only support DIMMs of up to 256MB each, for example.

SO-DIMM is a smaller form factor used in laptops. They are not compatible with DIMMs. You probably have DIMMs. You can take out one of your modules and figure out its type by its shape (length/width ratio and position of the notch).

PC2100 = 266 MHz DDR, PC2700 = 333 MHz DDR, PC3200 = 400 MHz DDR. Since you already have PC2700 and PC3200 DIMMs in the motherboard, I'd stick with those. I think that the overall RAM speed will be limited to the slowest DIMM, but memory speed doesn't matter that much anyway; it's rarely the bottleneck. I've always heard that memory will work regardless of speed (though higher speeds will be wasted on a motherboard/CPU that only supports lower speeds), but I've personally had a machine fail to start up with faster DDR RAM in it, so I'm not sure.

Don't get ECC (error correcting) RAM unless the motherboard supports it, which it probably doesn't. -- BenRG (talk) 00:05, 23 March 2011 (UTC)

Motherboard info: Under Device Manager I see the 2 motherboard resources listed as ACPI\PNP0C02\1 and ACPI\PNP0C02\2. On the motherboard itself I see:

Hewlett-Packard SP#323091-001 P6B58OF9VOWNSZ AS#305374-001 374 REV OF S2A

StuRat (talk) 02:13, 23 March 2011 (UTC)

305374-001 is the motherboard for a HP COMPAQ D530 - Can you see that anywhere on the back of the case which might confirm this? (I know you said it's a refurbished computer, but it's still quite likely they put it back in the original case) Looking up that model on the Crucial site gives this which suggests the maximum amount of memory you can put in it is 4Gb. Your safest bet though is to run the memory checker on the crucial site as that should correctly detect your motherboard and supply you with a page telling you how much you can have and what your options are.  ZX81  ^talk 02:26, 23 March 2011 (UTC)

Actually, apparently it's the same motherboard for the D330, D338, D530 and D538 so if you see any of those on the back that's good.  ZX81  ^talk 02:30, 23 March 2011 (UTC)

OK, I ran the Crucial scan, and it gave me some good info:

1) I do have dual-channel architecture. To get the most out of this, I should use matched pairs of memory cards. (However, they then recommended an unmatched pair.)

2) I don't have ECC support. Can I still use ECC memory, if it's cheaper ?

3) Max size is 1 GB per slot, for a max of 4 GB. However, they warn that only 3 or 3.5 GB would be accessible under my 32-bit architecture. (And then recommended that I get 4 GB, anyway.)

So, the scan seemed good, but their recommendations seemed faulty. StuRat (talk) 03:37, 23 March 2011 (UTC)

1)What does it recomend? Is it 128, 256, 128, 512? If it is the unmatched pair is likely because it's trying to use the RAM you already have. Also usually 1 is matched with 3 and 2 with 4.

2)No. Also I don't think ECC is cheaper.

3)I would also recommend installing 4GB to max the system, even if not all of it will be acessible. This is due to getting the memory matched.

Taemyr (talk) 03:52, 23 March 2011 (UTC)

1) There were multiple recommendations. The one resulting in a mismatched pair was to get a 1 GB card and leave my 256 MB card in place in the matching slot.

3) Wouldn't getting 3 (1 GB) cards avoid the mismatched pairs prob, since I would have a matched pair and a lone card ? (I'm assuming a lone card doesn't count as a "mismatched pair"). StuRat (talk) 04:46, 23 March 2011 (UTC)

It's not that mismatched pairs are slower but that matched pairs are faster. With a single module you won't have a matched pair. I think that you will still get the matched-pair performance boost on the other two modules, but I'm not sure. As I said above, though, I wouldn't worry about it. The benefit of adding more RAM is reduced disk access, and even the slowest RAM is so much faster than the disk that variations in RAM speed will hardly be noticeable most of the time. Also see Dual-channel architecture#Performance. -- BenRG (talk) 08:22, 23 March 2011 (UTC)

I have a follow-up question on item I. Do I get the lowest speed of all the occupied slots, or does that go by pair ? StuRat (talk) 04:56, 23 March 2011 (UTC)

AFAIK you get the lowest speed among all occupied slots. Rocketshiporion♫ 06:35, 23 March 2011 (UTC)

OK, thanks for the help so far, everybody. I've pretty much decided to buy a matched pair of 1 GB 400 MHz DIMM (non-ECC) cards. But how should I use them for best effect ? Here are my three options:

a) Use those two alone, in the same-colored slots, for 2 GB at 400 MHz on a single matched pair.

b) Use them with my current 256 MB (333 MHz), card in one of the other slots, for 2.25 GB at 333 MHz total, with a single matched pair.

c) Use then with my current matched pair of 128 MB (266 MHz) cards, for 2.25 GB at 266 MHz total, with two sets of matched pairs.

d) Use them with one of each of my current card types, for 2.38 GB at 266 MHz total, with one matched pair.

So, which would be best ? StuRat (talk) 22:19, 23 March 2011 (UTC)

I think you should upgrade your motherboard instead of your RAM, given how much cheaper DDR3 memory will be than DDR1, plus you'll get a drastically faster CPU. —Preceding unsigned comment added by 75.57.242.120 (talk) 00:43, 24 March 2011 (UTC)

I doubt if the cost of a new motherboard plus new DDR3 memory would together be less than just new DDR memory. Also, the speed of my motherboard is 2.8 GHz, which isn't bad, if only it wasn't hampered by insufficient RAM. StuRat (talk) 02:02, 24 March 2011 (UTC)

2.8 ghz is fairly irrelevant. See megahertz myth. At a guess a 2.8 ghz P4 dual core (P-D or whatever it was called) similar to yours (can't remember how much of a difference the cache size made on P4 I guess yours is lower cache and FSB since it's a Celeron) would perhaps be comparable 1 ghz Core i3 or worse (depending on app of course). I do agree however your system is severely limited by the amount of RAM. Whether it's worth upgrading I can't say particularly since I haven't looked in to the price of DDR RAM for a while). Nil Einne (talk) 12:44, 24 March 2011 (UTC)

I think it's worthwhile to try out the memory first. If it alone makes performance nice and snappy, then don't bother opening up the computer anymore. I don't have any advice on what configuration to install it in, though. Paul (Stansifer) 13:00, 24 March 2011 (UTC)

For old computers you may be able to buy cheap memory via eBay. 92.24.188.210 (talk) 20:22, 24 March 2011 (UTC)

I found this on Amazon: [5]. That's $56 total for "PNY OPTIMA 2GB (2x1GB) Dual Channel Kit DDR 400 MHz PC3200 Desktop DIMM Memory Modules MD2048KD1-400". Can anyone beat that ? StuRat (talk) 23:52, 24 March 2011 (UTC)