**For this tutorial, I will be using the current memtest available (version 1.70) as an example. The latest version is 1.70 to date (06 February 07)** First, download the program from here: http://www.techspot.com/downloads/500-memtest.html There are two types of downloads you can get, a bootable CD (.iso) and a bootable floppy disk. Pick one and download it. If you're experiencing troubles using the CD or Floppy versions, you may try the USB version, but I haven't tried it yet. If you use Dual channel or multiple sticks of RAM, take all of them out so you have just the one plugged into the primary slot. Run the test and swap with the other sticks until all is tested individually. Don't forget to turn off and unplug your PC before removing/replacing any components It is suggested that you run the test for at least 7 Passes. You can run it longer or shorter if you wish but note any errors it states on the information it gives you onscreen. If you do get errors, that means that the stick you have currently is incompatible or faulty or if you're lucky, its only a dirty slot or contact on the module/motherboard. If you don't get any errors, put all your RAM sticks back into its slots and run the test a final time and observe any errors. There is also menus, infos and things you can change inside the program. Fiddle if you want to, but don't ask me what they do.. Memtest CD: Download the ISO current version (memtest86+-1.70.iso.zip) to your PC. -Extract the .zip file to a location that you know, like the Desktop or Downloads folder or next to the .zip file. You should end up with the file Memtest86+-1.70.iso *Note* If you have WinRAR (or similar) installed, it will look like an unzippable archive with nothing inside. Do not open it with WinRAR. -Go to your favorite CD burning software, and choose to burn from an image file. Simply point to the memtest.iso file and hit the "burn" button. Eg: Nero>Disk Image or Saved Project>[select the memtest iso file]Ok>Next etc. -Insert a blank CD into the drive and let it do its magic. -Presto, you have a memtest bootable CD. Simply leave the CD in the drive and boot from CD by pressing a key (if needed) then running the test. Bootable Floppy Disk: Download the package current version (memtest86+-1.70.floppy.zip) to your PC. -Extract the zipped file to a location that you know, like the desktop or folder etc. You should end up with a folder named floppy -Go into the folder and double click on the install.bat A command window will pop up asking you for a location of your disk drive. Insert a blank floppy disk into the floppy drive, then enter the letter of the drive (usually the letter a) then follow the prompts. -after it creates the floppy, simply boot your PC with the disk still in the drive and run the test as advised. After you've set the test, grab some coffee and a magazine or go watch tv etc. It will take a while. **Problems FAQ** Q: I put the CD/Floppy disk in and rebooted my PC and it still didn't run. A: You may need to select the boot device by pressing a special key or change the boot order of your PC by entering BIOS/Setup. While your PC is starting up, there is a button you have to press to enter it. You can find it by looking for "Press .... to enter SETUP". Most comonly the DEL key or F2, then looking for "Boot devices" or "Boot order" or similar, then following the onscreen prompts to change them. Q: I have no floppy drive.. A: Use the CD version Q: What if I want to run the test overnight? A: Go ahead. If you have the patience.. Q: Is this test entirely 100% accurate? A: Yes and No. I would actualy treat these tests as more of a guideline, since there are other factors that can play into having hardware/RAM trouble. Most common example would be mixed and matched RAM, where both test out OK but when put together won't let your system boot etc. (although there are cases that mixed RAM works fine on most people's system - but that's motherboard dependant.) Some others are under-powered systems etc. If you want a second opinion, there are other memory diagnostic programs out there, and one built into Vista (type in the search bar memory and click on Memory Diagnostic Utility. Follow the instructions and reboot) Q: Test comes out OK but Windows/OS is still giving me errors? A: You can try another new set of RAM if you wish (as per comment above), but you should now be focusing on finding out if it is a windows problem (since this test runs pre-windows boot) or other hardware related problem. I suggest striping your PC to its barebones components where possible then start troubleshoot from there. Some good information about RAM and the do's and don'ts from Tedster can be read from here: http://www.techspot.com/vb/topic47210.html If anyone has used the Linux packages (.gz), the binary and/or the USB versions, can you please post your own tutorials here or PM me and I'll edit into mine, with credit to you.