won't boot with driver

[zhi]

My specs.
AMD Athlon 64 X2 4200+
BIOSTAR TForce4SLI 939 NVIDIA nForce4 SLI ATX AMD
Antec TRUEPOWERII TPII-550 ATX12V 550W
EVGA 256-P2-N516 GeForce 7800GT 256MB 256-bit GDDR3 PCI Express x16 SLI
Western Digital Caviar SE WD800JD 80GB 7200 RPM SATA 3.0Gb/s
Kingston ValueRAM 1GB (2 x 512MB) DDR 400 x2
Window XP

I have this problem since I tried to install WC to the GPU. The computer will boot with this video card, but during the window loading, there always like 3 columns of small red boxes. Once the window is opened up everything seems fine, but when I tried to install the driver for the GPU the computer will reboots during the processes. There was a time it successes the installation with different driver, but the computer keeps reboot itself before the window loading. >_<
Then I have to open up the window in safe mode and uninstall the video driver to solve this problem.
Any idea what’s going wrong with my video card?
And also, what does driver do?

Thanks

 

[utaka95]

Could be a bad video card, ram or power supply. Try running Memtest86 on it to eliminate the ram as the problem, if it's not bad, try another video card to see if your vid card is bad.

 

[zhi]

It is bad video card, I tried w/ my other 7800gt it wroks.