I think this is a critical update issue with the Pentium 4.
My dad has had a P4 runing XP service pack 1, for over 6 months and it has worked very well. In fact, the speed and noise levels of his system encouraged me to trade up my Athlon for a P4 (and now I'm quite sorry).
About a month ago, he started complaining about sudden freezes, where the mouse would lock up for about a second or so. This happens regularly about every 15 seconds or so for a few minutes, then it would go away. Recently, within the last few weeks, he started complaining about hard resets. Not the BSOD, not a lock-up, but a hard, sudden reset, with no hard drive access, like you pushed the reset button. He has an Asus board with Corsair memory and an Antec power supply. This is NOT cheap hardware, so I was quite baffled.
After "upgrading" from an Athlon to a P4 2.4, I started having similar problems with Win2K service pack 4. Sound in Mediaplayer and Goldwave would skip for no reason, I started getting the BSOD frequently (which I didn't get for 2 years with my Athlon). For the hell of it, I re-installed my system to clean out all the Athlon stuff left behind and did all the WindowsUpdates. Now my system still crashes occasionally, and now gives me the dreaded 1-minute shutdown notice from TASKMGR.EXE. I've gotten that one twice in the last week and it's really getting on my nerves. Memtest86 shows no problem with my memory. FlashPlayer6 (several revisions) are well known to crash like crazy on the P4, but that's all I know.
I really want to know if this is a P4 issue, or if MS is screwing things up, again. If this keeps happening, I might just call my P4 a loss and see if my old Athlon 2600+ fares better.