I've had my HD7990 for about two years now and only had a few minor problems with it, usually only related to crossfire support problems with specific games.
For some reason after updating to Windows 10 and installing the 15.7.1 drivers I've gotten a very strange and disruptive problem any time I try to play The Elder Scrolls Online (I played it just fine before updating)... Right after the update it started as a simple graphics bug where sometimes character models would flicker and/or disappear. Switching the game to DX9 mode fixed the issue but caused crashing problems, so I went back to DX11 mode and just dealt with the flickering.
Now over the last few days the problem has progressed to where when I launch the game, nine times out of ten the entire screen starts to flicker with static and distortion. The only other time I can recall something giving this visual effect was many years ago when I was running dual nvidia gtx 870's in SLI and one of them died. It's just a full screen flashing with vertical lines and tons of distortion.
This effect persists all the way through the login screen and loading screen, but goes away once you're actually into the game itself... Except on the mouse cursor (which flickers when in free-mouse mode), or during further loading screens. The game itself runs perfectly fine aside from still having the character model flickering it originally had, with good frame rates and very rare crashes (one time out of maybe 20 hours or play). However, if I alt+tab out of the game or close the game - normally, or through the task manager - the crazy static/flickering effect persists everywhere until I reboot the computer, then it's fine again.
This doesn't happen in any other game that I play, and I've tested it with Dirty Bomb, Planetside 2 and a few others with no issue. I'm a bit lost on what could be causing the problem, or what to do about it other than either run in DX9 mode and deal with frequent crashes, or revert back to windows 8.