I recently redid my Windows 8.1 install, and I notice artifacts, like bars on the screen, things looking corrupted or off for a split second before going back to normal. It's not a GPU issue as this doesn't happen when using Windows 7, and the GPU can be overclocked quite far before stability is a problem. I wonder if it could be caused by Aero Glass as I could see that causing issues like this, but I'm not sure. I'll try different drivers and a different version of Aero Glass soon.
Edit: Tried 441.66 and 474.06, and they both have this issue, going to try 431.36 next.