Headphones not recognized

I was minding my own business by playing a steam] game, suddenly small green boxes appeared and spread all over the screen like som kind of virus. and then my screen shut down and was on power saving mode. after a few tries of trying to revive the screen i unplugged every cord connected from the computer to the screen and shut down my computer. after som waiting looking att 9gag I reatached it all and turned on my computer. it said there was an error starting the computer, when i tried to rewatch a youtube video I could not hear anything. tried to fix the sound by right-clicking the sound icon but there was no use. then i found out that my computer doesnt recognize my headphones.