Did your windows turn grayscale?

And you don’t why. You are not alone. And it is not a virus.

You probably pressed CTRL+WINDOWS+C accidentally and nobody told you 🙂 Press it again and you are done!

Symptoms: the whole screen is greyscale, tyring to adjust balances in graphic driver doesn’t help and resetting the computer doesn’t fix the problem. Also when UAC runs, the grayscale filter is not applied.