This happened on my original "upgrade" install of windows and a "reset" install. So, I then went ahead and did a real fresh install.
I formatted my hard drive and downloaded a fresh iso of windows 10.
I then installed windows 10 pro 64 bit on my machine.
Then, I downloaded and installed the windows 10 64 bit driver.
As soon as the drivers are installed, the system crashes all the time. There are notifications that pop up in the bottom right noting that the driver crashed and recovered. Radeon Settings (the program) doesn't even usually manage to load before itself crashing. Most games (rocket league, this war of mine) stutter and freeze nearly every second. Some didn't even open (saints row the third, fallout new vegas). Poly Bridge was *okay* (not great, but playable). Occassionally, the screen would go black and not return. Sometimes, I'd blue screen into a video_tdr_error (atikmpag.sys). Even videos in VLC froze every few seconds.
Here's the real kicker though: I then installed Ubuntu instead. I installed the drivers. It all worked great. Portal 2 = 1080p 120 fps (sync) on nearly max settings. Saints Row on the max settings that didn't use directx at 1080p 35fps. Poly Bridge was also great. Videos are great. The system is stable.
So, that's weird. Flawless Victory on Ubuntu 16.04.1 with no effort. Windows 10 = suck.
The only reason I care to fix this is that I have games I prefer to play on windows 10 and I don't want to set up some weird VM with gpu passthrough or whatever.