For some reason some of my games will freeze completely sometimes while playing them. The computer becomes completely unresponsive and i have to press the power button to shut it off and then power it back on again. so far it has only happened in Mafia, and diablo 2. It doesn't happen often just once in a while, about once every 2 weeks or so..This is an older amd 64 3500+ pc with 1 gig ram, 2 ide hdds, its good enough for the older games I play. I'm just trying to figure out if its the game or maybe the hardware has some type of defect. Is there any software tools to test your hardware for defects? Thanks.

Why didn't you list the video card? "If my answers frighten you then you should cease asking scary questions" - Jules Winnfield (Samuel L. Jackson) in Pulp Fiction

can you get into the bios and check temperatures immediately after a lockup? maybe your PC's insides aren't cooling as well as they used to, and are in need of a good dusting (compressed air, no vaccuum). This is an even more likely explanation if the lockups happen after extended periods of gaming, as opposed to right in the first few minutes.

Sorry i hadn't replied sooner i just was very busy with something else. Anyway, like i said my computer is old, and its an old cheap stock Amd 64 +3500 with 1 gig ram with ati radon xpress onboad chip video. The onboard heatsink seems to get pretty warm and they didnt even put a small fan over it. I know on-board video sucks but i didn't have money at the time to get stuff for it not to mention i knew the hardware would be better in the near future so i saved my money for a better pc. I'll probably end up taking the HDD's out and selling it.