video issue - Asus A8SC

hello, is it possible to replace the graphics adapter for Asus A8Sc? it seems that my current one is defective

if you're wondering why i think that its defective, these are my findings:
- it keeps on rebooting, it rebooted for the very first time while browsing
- thought that it was a problem with winxp but 'twas the same with win7 (dual boot)
- thought that it was an OS problem, so reformatted both OS
- reformat with winxp only, no go
- reformat with win7 only, same thing
- stick with win7 to troubleshoot
- thought that it was a fan issue, so i opened and clean it
- run HD Test and mem test, test passed
- have not tested mobo since it can't find a software to test it
- no problem in safe mode before and after reformatting
- reboot does not occur after a system restore
- noticed that after an automatic update, problem would happen again
- did not include NVIDIA update the next time
- reboot did not happen anymore
- tried the oldest and latest NVIDIA driver, reboots happen
- tried the force NVIDIA install, same thing
- now i am stuck with the VgaSave driver with no adapter type
Input/Output Range 03B0 - 03BB used by:
Mobile Intel(R) PM965/GM965/GL960/GS965 Express PCI Express Root Port - 2A01
Input/Output Range 03C0 - 03DF used by:
Mobile Intel(R) PM965/GM965/GL960/GS965 Express PCI Express Root Port - 2A01
Memory Range 00000000000A0000 - 00000000000BFFFF used by:
Mobile Intel(R) PM965/GM965/GL960/GS965 Express PCI Express Root Port - 2A01
- sometimes instead of 1280x800 resolution, 1024x768 would only be the max
- if you look at the screen closely, you will see lines
- editing pics is a hassle

please advise for other steps needed why laptop continually reboots once NVIDIA driver is installed
and if it is indeed defective, can it be replaced? if not, is there an external video adapter?

 

It seems that it is replaceable, it is probably a faulty 8-series card (nvidia underfill).

There is a high res pic of the motherboard here:
Asus A8S A8SC Motherboard PM965. 2 Months Warranty. | eBay

You may be able to replace it with another card, but I was unable to find pics of the Asus 8400M G.

 

thank you very much