Freezing issues

[Harbringer]

When playing any game, as low as warcraft three even, after a while my system completely locks up and I have to hard restart, I initially thought it was an overheat problem, and thus, like a moron, managed to get my computers graphics card temperature down in the twenties.......I have my system cleaned out, i started removing a whole bunch fo stuff, I have no viruses(I constantly check) and no spyware, trust me its clean. Im running and Nvidia 6800, more than adequate to run my gams(COH on low setting, Supreme Commander and warcraft III) yet they all lock up and freeze out of nowhere, heres my specs:

AMD athlon XP 3200+,MMX, 3d now, 2.2 GH
1 gig of system ram
Nvidia 6600 256 MB
Windows XP
direct X 9.0

Help is apreciated, Its gettting very frustrating, I just want to be able to play my games without having to worry about random lockups.

 

[HAND]

I'll assume you have a patched up version of Windows XP SP2 with lastest chipset and graphics drivers.

What wattage PSU do you have and how long has this been a problem?

I had similiar problems running Counter-Strike Source and RTW and eventually upgraded to 500watt Coolermaster PSU which solved 90% of the problems.

Try this link to give a ball park figure. I might be wrong but its worth checking to see if your PSU can stand up to it.

 

[BirraImperial]

I could also be bad RAM. Does this happen only when playing games or randomly?