I finally compiled my new system (p IV 2.4 ghz, 512 mb ram, 80 gig hdd, radeon 9700, sb audigy and a dvd-rom; all on a asus P4PE), however whenever I use it for 3D games or transfering files to my hard disk or even a divx encoded movie, it shuts itself off. no error message or such, just pfeww.
Probably a power or heat issue but by default when Windows XP encounters a system failure, it reboots without warning. The system failure could be do to poorly written software, that is, maybe there's nothing wrong with your computer at all. For example, an early version of Roxio Easy CD creator caused Windows XP to reboot. The setting that controls this can be changed:
Go to -> Control Panel/System/Advanced/Settings (Startup & Recovery)/System Failure/Uncheck-Automatically Restart.
Warning: I've only seen this work in one out of one cases. This may allow for unpredictable results.
This also can be done in Windows 2000 Pro. Not sure about Windows 95/98/Me/NT. Check your available documentation.
This didn't sound like it was the right solution, as the pc doesn't reboot at all, just shut itself off. i tried it nevertheless, however it didn't solve the problem
now, regarding the heat issue: what could I do to see if this is the problem?
From here you're going to have to do a process of elimination. First, underclock your processor by setting the FSB to 100MHz instead of 133MHz. If you have access to another graphics card, different from the ATI 9700 Pro, try replacing the ATI 9700 Pro with that card. Preferably a card without a cooling fan.