So, i never had this issue, and now it really freaks me out. So i was surfing on internet, but not in maximized window, in smaller window so i can see desktop aswell, and what happened is, my desktop became darker for 1-2 second. Now when i say desktop i mean only the background, not the opened window, and that same thing happened more times. I even restarted pc, and saw that again. So now i dont know what that could be. I never had that issue, this is first time, should i be concerned? Please help, how can i know what causes that, and how to fix it?