>I think its time for you to reinstall windows, ne?

No.
Lock-ups often mean low-level buggy drivers, and I have the latest.
I suspect that one of the culprits to be the drivers for my on-board ethernet card, because it sometimes crashes after I stop a download. Reinstalling Windows won't make the buggy drivers become magically debugged. As for buying another one, I bought two and they don't work. They get recognized etc but they dont initiate transfers. At least the integrated one works most of the time.
Another surefire way to lock XP: clicking on the "!>" (eject?) icon of MediaPlayerClassic. Buggy MPC? Buggy DirectX? Dunno. I have the latest versions. I just have to be careful to never touch that icon.
I would have preferred an alt-ctrl-del because I believe that a-c-d can close open files before a reboot. Well, on Win9x it did, I got no scandisk penalty that way. On XP + NTFS I'm not sure - scandisk never kicks in after a hard reboot.