Yea man bad drivers, been loads of posts on here about it.
Uninstall and then install 12.1.
Ditto. Same problem here. The quoted suggestion fixed it. On a side note, this is the very first issue I have ever had with Skyrim, and it's not even the game's fault. Don't get me wrong, I like my HIS 6790 video card, but stuff like this makes me wonder if I should switch back to nVidia.