Pixelated battle.net launcher

for a few weeks now I haven’t been able to play CoD MW, suddently the game is laging like my PC can’t run it. But I have been playing for a year now i don’t Know why I suddently can’t make it work. I have noticed that the battle.net launcher window is really pixelated (like a wrong screen resolution) and i can’t bring it back to normal. the text is a little blurry, the icons are bigger, the window is bigger, maybe this is linked to my problem with CoD MW. My graphic card drivers are up to date.

thank you