I'm running Windows 7 64bit, 8gb on a Asus motherboard. I installed my TBS 6981 about 3 weeks and everything had been working great until last week. I had been messing around with graphic drivers on my machine and then I started having start up issues - I could boot windows. I thought this was due to the graphic drivers and I had wanted to do a reinstall of Windows 7 anyway so I reinstalled the operating system and started from scratch. Everything was fine until it cam to installing the 6981's drivers again. Everytime I installed the drivers I'd get BSOD. Restarting the machine was hit and miss - sometimes windows will boot but other times I have to take the card out to get into the operating system. The best I've managed to do now is get into windows, get into device manager where there is a little yellow exclaimation mark next to the 6981 entry claiming the device is not started.
This is so frustrating because the card was working like champ and now it seems to be malfunctioning. Worst still I think this could be a hardware problem which would explain why it was working fine. I've also tried it in the other PCI-e slot in my machine. I suspect you'll suggest trying the card on a different board - I'll try that tonight and report back.
Just want to reitrate that I was loving the card until this starting happening so I really wanna get this fixed!