I will soon be adding 1Gb (2 x 500Mb) of used memory to a Dell GX280 XP Pro system. 1. Is there an memory test utility in XP, or can someone suggest a good (free?) downloadable utility? I don't have the XP disk as the unit was bought used. I have done a search here for such and all I see is dozens of gripes about BSOD failures after XP updates. Scares the ____ outa me! Hope MS can figure this one out and fix it quick! 2. There are 4 DIMM memory slots on the mobo. Is there a particular order in which the DIMMs should be installed? Pls adv. Any help will be appreciated. Thx

I would really hesitate to add used memory unless someone is giving it to you. Certainly I would never buy used memory when new memory is so cheap. Here is a link to the memory requirements of your Optiplex: http://www.crucial.com/store/listparts.aspx?model=OptiPlex%20GX280%20%28Desktop%20and%20Mini-tower%20Models%29 And in case you have the small form factor model: http://www.crucial.com/store/listparts.aspx?model=OptiPlex%20GX280%20%28Small%20Form-factor%20Models%29 As you can see, 1GB of new RAM is $31. Not very much to spend.MS-MVP - Elephant Boy Computers - Don't Panic!

Malkeleah - Thanks for the heads up on the new memory, but I'm ok on this job since they came real cheap. That site did seem to indicate that there was no particular installation order required nor a fixed number of modules. Do you know whether XP Pro has a memory test utility or not? If it doesn't, can you suggest one? Thx

XP Pro doesn't have a built-in memory test. I use Memtest86+ from www.memtest.org . Here are instructions about getting and using this utility. If you already know how then just skip the rest; I'm not trying to insult your skills but only want to be thorough. You will download the .iso to make a bootable cd. You want the pre-compiled bootable ISO (.zip). Unzip the file you download by double-clicking on it and drag the contents out. You will now have a file called memtest86+-4/00.iso (the version number may be different). You can delete the .zip file now. Put in a CD-R disc and start a third-party burning program such as Roxio, Nero, or the free ImgBurn (unless you have Windows 7 which can burn .isos natively). You will need to burn the file as an image, not as data. Refer to your burning program's Help if you don't know how to do this. Leave the CD-R in your optical drive and restart your computer. When you restart the computer you will see messages: 1. Possibly a message that says something like "Press F12 for temporary boot menu". If you have this message, press that function key. Use your arrow key to select the CD/DVD drive and the computer will boot from the Memtest86+ CD you made. 2. If you don't see a message about a boot menu you will need to go into the BIOS to change the boot order. This message will say something like "Press F2 to enter Setup". Press that function key and you will enter the BIOS. Find the section about boot and change the boot order to CD/DVD drive first, hard drive second. Save your changes and exit Setup. The computer will boot from the Memtest86+ CD you made. The test will run immediately. You can remove the CD while the test is running.MS-MVP - Elephant Boy Computers - Don't Panic!

In addition to memtest86 as Malkeleah indicated, there is the Windows Memory Diagnostic.