Keyboard stops working system-wide, have to restart computer?

Twice now today in game my keyboard has stopped working. It's never happened before (in league, or any other game). It's happened during league games both times today. the keyboard no longer functions in windows at all, have to use the mouse to reboot. Once I reboot, all is well. My teammates are probably not too happy about it though.

Any other reports of this? Any fixes? Razer Black Widow Ultimate.