First off, I'm a sysadmin, but I'm pretty removed from home computers and gaming machines. A friend of mine asked me to look at an issue on his machine where it was hard locking sometimes, or there were artifacts all over the screen. He is/was running dual Nvidia 8800GT cards in SLI. I'm unfamiliar with how SLI works, but I would think that it would work with only a single card. The machine doesn't get to a login screen with both cards installed, it will usually lock during the Vista splash. Out of the 2 cards, one of them causes all kinds off issues on its own, so I'm pretty sure its no good. However, when using the other card by itself, the device manager says that the device isn't started. In the Nvidia control panel, there is no SLI or Physx options to turn off SLI, which I would expect, as there aren't 2 cards physically installed.. Is the error in device manager to be expected because the second card isn't present, and windows is expecting SLI?
Things that have been done:
-Latest BIOS on computer
-All chipset drivers updated
-Latest drivers from Nvidia
-Tried each card one at a time.
What is the possibility that both cards are bad?