Needing some help sorting out a vid card issue

[bomath]

Allow me to doubt that the card is defective; I think 75% of the RMAs are not justified, and the vendors only send back replacements because they don't want the bad PR that would come from some loudmouths there.

I see that you did almost everything BUT a nice clean install for the Windows. I had the exact same experience a couple of times, when switching from nVidia to ATI cards and back to nVidia, solved only by a clean Win reinstall.