Originally Posted by eternal7trance
Stupid question but did you try using a different monitor and making sure you're using the motherboard standoffs when you put in the motherboard?
Not having standoffs wouldn't cause it to not game. It would cause problems much sooner than the point where you realize you're game isn't working.
Originally Posted by robwadeson
You also swapped the psu?
Edit: You will need to install directX if you haven't already done so. A fresh OS install doesn't include directX
OP says he tried a different PSU.
If you have formatted it's not software. Unless you have some program conflicting but I've not heard of any that are biased against games.
What is you're monitor setup? 1, 2, 3, 34? The problem doesn't seem hardware. When you figure it out you're going to slap yourself I bet.. It's probably something stupid that no one will think of.