Green Screen with Hardware Acceleration Disabled
I am having the EXACT same problem. The screen on Youtube for example goes screen and then fastforwards automatically (while still being screen). Sometimes (very often) the playback from a video restarts - randomly, without me doing anything.
Don't know HOW or WHY this happened. It have always worked before... Until now. Stupid Flash.
Got the latest Flash version, latest GPU drivers and latest Windows updates. Using Chrome, and their built in Flash plugin is activated.
Dxdiag log @ pastebin:

How can things like this even happen without me changing shit in my system? Stop making stupid changes on your updates.