Okay, I have this problem (had it for a long while now) where my computer would COMPLETELY freeze up that is unescapable without hard-resetting the computer.

Details:
While I'm playing Jazz Jackrabbit 2: TSF, the game works right, but at one point while either in the middle or at the end of a level, the game would just suddenly FREEZE with a stuttering sound of what happened just then. This has been happening not only on this game, but it's happened to a few other games as well, INCLUDING Rescue from Space Invaders... (surprisingly it didn't affect Quake III arena but Postal2 won't go beyond loading because of this. Worms World Party even!)

Information you need to know:
Processor: AMD Duron 950mhz
Audio: SB Live! Value using Web drivers from official site
Video: nVidia GeForce4 MX420 with 64MB SD-RAM
Motherboard: VIA KT-133 chipset. Brand is EPoX, model EP-8KTA
OS: Microsoft(R) Windows(tm) XP(tm) Professional with SP2(tm)
HDD: appx. 80GB Seagate Barracuda
DX version: DirectX 9.0b
Anti-Virus: Norton Antivirus 2003 Professional Edition
System Restore: OFF
Run Spyware scan: Yes, with latest references on Ad-Aware 6 pro

Other information:
Strangely enough, sometimes running the DirectDraw tests would freeze the computer the same way..! I'm forced to playing some of these games in windowed mode, but I can't do that for all of them.

I'm asking for desperate need of help. Instructions on how to log the problem, please tell me!
Any other ideas will be GREATLY appreciated, this problem has been bugging me for ages now so I'm kindly asking if anyone could help me out here.

Thanks in advance!