Shortcut - Suddenly only 37 FPS max?

I might have pressed a key combination while playing Fortnite or something and suddenly a small window appeared on the 2nd monitor which was then closed again. And zack only 37FPS maximum? What's this?

Screenshot?

Dunno, still got max 37 FPS in the lobby? No other apps open or anything? Possibly an FPS limiter? Didn't install one? Vlt GeForce Experience?

I had something like that at Minecraft. I then installed Windows 7 (previously Vista) and it went away.

Hmm funny. Is caustic from 120 FPs to 37 … Nothing works anymore!

Try a new Windows from USB or DVD and then it should work again

Switch on and off.