About a year ago I set up a computer for my girlfriend and it constantly crashes with BSOD. I looked at it and everything looks fine. It's an HP so I even used the Recovery discs to reinstall XP. It still crashed with "STOP 0x0000000a: IRQL_NOT_LESS_OR_EQUAL" error. It was especially bad if she was playing Sims2. I finally just told her it must be something she is doing.
Low and behold, this week MS releases a patch, (http://support.microsoft.com/kb/929338) and I have to eat my own words. Hopefully this takes care of the problem. If it does, thank you, another relationship has been saved! ( j/k)