Help! Unexplained PC Crashes - see inside 4 details

[chemicalplay]

Athlon Xp 1800+
Gigabyte K7 Triton
20gb Seagate HDD
384mb DDR Ram Pc2100
PNY Nvidia GeForce MX 440 64mb DDR
Creative Sound Blaster 4.1

I have a newly formatted HDD with windows xp and other stuff, i install a game, play for 10mins and the whole pc locks, i have to reset.
This happens with nearly every game i own, excluding games pre-2000 and microsoft freelancer (cos its made by microsoft dur!).
This is very frustrating and has caused me to reformat many times to try and solve the problem.

HELP! Post for more information.

 

[PhaZe]

This is a shot in the dark but is there adequate air flow in the case? It could be that the video card is over heating?

 

[dbwillis]

CPU overlocked? maybe its heating up/.//