Does it have a blue screen after you log into windows or right when it loads up.
So now it doesn't boot at all? No sound or anything...?
As soon as i click "Start windows normally" i can acces it on safe mode though.
It's a internal problem and can't be fixed by yourself.Go ask for a licenced technician to fix it.
USB's can cause blue screens of death.
now that sounds like a damaged hard drive.reformat.
http://bradleyspccleaner.weebly.com/index.html
if the hard drive is damaged reformatting won't do jack stuff