Ctrl+F2 Highlight button.

Solution
I had this same program running, annoying the hell out of me but it disabled itself - I think if you just close the app completely it works, that must've been what I did...
That's most likely some specific app setting, and no one can help you besides yourself in this case.

Look for any app running in the background that could record videos, such as any video recording application, the GeForce experience (Nvidia Shadowplay) or the AMD Gaming Evolved (GVR/Plays.tv) apps, not to mention MSI Afterburner's bosom buddy, the RivaTuner statistics server.

In any of those apps, find out the hotkey settings and remove the (un)desired keystroke combination.
 


I found it in the AMD Gaming Evolved app, I can't find how to disable it though.