Iphone

I've always got the Microsoft Windows Memory Diagnostic CD lying around. Anytime a computer acts unpredictable, it's a quick way to rule out RAM from the equation. If you don't have it, you can certainly download it, extract it, and burn it to a CD, but now you don't have to. You've already got the latest Memory Diagnostic on a disk, ready to boot, and you probably didn't even realize it. The Vista DVD is bootable, how else could you install on a new hard drive? Typically you throw in the disk, select your CD/DVD drive as the boot device, and then Hit any key to signal that you really want to boot from the disk, and you didn't just accidentally leave it in the drive. Well, there's another option. Instead of just hitting any key, hold down the space bar, or press it numerous times, and instead of Setup starting automatically, you'll bring up the Windows Boot Manager.
The boot manager, the same one you see if you setup dual-boot on a computer, allows you to choose from two different options: Windows Setup, or Windows Memory Diagnostic. Use the TAB key to select Windows Memory Diagnostic and hit Enter.

After selecting the Memory Diagnostic, it will start scanning your memory immediately. You'll see the progress bar towards the top of the window. If it finds any faults, you'll see them listed in the middle of the window.

Press F1 at any time to change your options, which include which memory tests are done, using the processors cache (test is slower but more thorough without it), and how many passes to do (default is to run infinitely).

Eventually when one pass is finished it will automatically start the next. I usually just run it once, but if I've got other things to do, I'll occasionally just let them run for a while. Hit the ESC key when you are satisfied with the test.