Hey guys. I joined this forum specifically to ask this question because i really dont know what to try anymore.
First of all, specs:
AMD 64 4000 proc.
Radeon X1900 512mb
1GB RAM
Asus A8N5X mobo...
Modest, but its always worked just fine for me until recently. It started when i tried to play Orange Box and every single game in it would crash my computer, completely shut it off, not restart it, completely off, whenever i tried to run in fullscreen. Everything works just fine in windowed. I thought it was a fluke until I d/led the new Crysis demo and it did the same thing. The strange thing is, all my other games still work fine in fullscreen. I updated my video card drivers, got rid of all useless programs, made sure nothing unneeded was running in the background, and even updated my BIOS even though it scared me. Still the same story. Any ideas?

Hi is your directX upto date? here Download details: DirectX End-User Runtime