ASUS V8420 (GeForce4 TI4200)

[ultimateswan]

Computer is rebooting, whatever I’m doing (WORD, games, surfing on the WEB even if my computer is idle.)

When I’m playing a game such as Unreal Tournament 2004, game play fine until it become very slow with strange behaviours like:
- White (sometimes coloured) polygons appearing on screen
- Black screens
- Lost of colours
- Keyboard not responding
- Crashes (Game)
- Crashes (Windows : BSOD, STOP error (different causes time to time)

Sometime the game don't launch with errors messages like D3DERR_INVALIDCALL, D3DERR_OUTOFVIDEOMEMORY

It happens in all games I play. I tried:
- Formatting my hard disks (including re-installing Windows)
- Several drivers from NVIDIA and Microsoft
- Removing one by one peripherals from my computer
- Installed all patches from Windows Update (SP2 too)
- Changed memory (RAM : 2 x 512 DDR PC3200)
- Updated BIOS drivers (tried up to v1004 and v1005 beta)
- Manually set parameters in BIOS for VGA Card and RAM
- Disabling / Enabling integrated peripherals in BIOS
- Changed Video Card ( Now all’s working fine with an ATI Radeon)

I was thinking that my video card was deffective so I return it to ASUS, but when I received it back, on the RMA paper, it was wrote :

Repair Result : No trouble found
Action : No trouble found

So what is the problem ? Do I need trash all ASUS components I have in my computer and buy something better ?
_______________________
ASUS A7V880
ASUS V8420
Antec SL450
AMD Athlon 3200+
1024 DDR

If you need more informations, ask me.

Thanks

Vincent,