Hi all,

I recently had to reinstall W10 after the anniversary patch messed up my os in a big way!
No problem, I just reinstalled and put all my drivers back on and had everything up and running in no time.

Except I have now discovered something slightly annoying...
I like to have a movie playing on my second display when i play games.
I play World of Warcraft and world of tanks mostly, they run absolutely fine at 100+ fps.
But any movie i have playing on my second display lags, micro pauses in the frames, like it's running at 15fps or something. I also see horizontal lines or blocks that appear randomly on the screen.
If i select the second display as the focus, and the game window in the background, then the film runs smoothly, no issues. Likewise if I am not playing a game then the film plays fine too.

I have tried both WMP and vlc, they both act the same.

I would like to note that before i had to reinstall W10 everything worked fine, no problems at all, it's only since then it's been lagging/stuttering. So i do not believe it is a hardware issue.

Primary Display is set as main display and focus. Geforce experience is not installed, presume it's still buggy/broken.
Xbox app has been removed, transparency has been turned off.

GTX970 x2 in Sli
Intel 4970k
8Gb ram
1st Display is Dell S2716DG 2560x1440 @144Mhz
2nd Display Dell 2407 1920x1200 @60Mhz

Any suggestions or help anyone may have would be greatly receieved.