Responsive issue when playing games

I honestly don't know if it's my graphics card or games not responding but just recently when I started playing the screen would flicker or stutter. What I mean by this is the game would continuously stop and respond again. Also when I am in fullscreen every time I click it flickers to my desktop then back. If I click enough times, the game would return back to windowed mode. It's not just one game, it's every game I play. It's not that my computer is too slow because I never had this problem. Does anyone have an idea what is going on!?

nevermind i found the solution! My registry had incorrect values so i copied different values from a fresh account and it worked!