1. The heat test. I know you have fans and such but remove the case cover and try again...
2. The speed test. Drop the FSB setting from 133 or 266 ro 100 or 200 and see if the unit works.
3. The RAM test. http://www.memtest86.com Only zero errors is a pass.
4. The pest test. Adaware, Spybot, Stinger and Housecall.
5. The P2P test. Got P2P? This test failed.
6. The BIOS test. It's likely out of date. Find out.
7. And the drivers. A test of today's builders is that they find all the current drivers. Microsoft doesn't do this for us.
I have been experiencing computer freezes whenever I am downloading from the internet and running a movie, video, music, or some other form of multimedia. Lately it has been happening ALOT when I run Unreal Tournament 2k4. I am running a system that is home built, WIth a Soyo KT400 Dragon Ultra Mobo, an ATHLON XP 1800+, 512 MB Pc 2700 Corsair RAM with a heatsink and a Nvidia FX 5200 video card with 128 mb RAM. I have a 450 watt power supply (tru power) and keep the computer very well ventilated and dusted. I have also run adaware repeatedly and this does nothing to help. I am also on a VERY fast cable modem connection.