Computer lockup after 15 mintues

After removing a rather annoying piece of malware I ran into a rather unique problem. The computer would start up normally and idle indefinitely, but after running any given program for about 15 mintues the computer would lockup. I would be able of ctrl+alt+del once, but task manager wouldn't appear if I tried to pull it up. I would still have mouse control, but nothing else would respond after that. After the fourth time this happened in succession, I attempted to do a repair install of windows, however, the repair install hangs after five minutes. Please help?

Specs:
Dell Windows XP laptop
Core 2 Duo 2.2ghz/core
2g RAM
Nvidia 7900
98g HDD
Enjoys long walks on the beech.

Please help me geek police?

Have you tried pulling you memory sitcks out and only using 1 at a time. What ive noticed when windows hanges during install is usually a bad memory module or bad hard drive.

I'll give it a try, but the diagnostics showed clean memory and drive.