I need help regarding my computer..! urgent help required?

-okay so awhile ago i was using the computer and thought of transferring a movie from the pc to the laptop via a pen drive however before actually loading up the pen drive on the pc i did a manual virus scan and it showed up nothing so thinking that it was all safe to go ahead i opened up the pen drive contents and proceeded to delete everything that was already in there to make some space for my movies...however when i selected everything at once a window popped up saying if i would like to select the hidden files as well and then it gave me directions on how to view those hidden files...after following those steps i found some pretty weird named files, first instinct in my mind was virus files so i deleted everything at ones including the files already had on my pen however still wondering why my antivirus didnt manage to pick it up! and now the problem seems to be is that my keyboard has stopped working and everytime i press a key it gives me an error sound and when i select something on the desktop or try to open one of the icons from the desktop bar it just wont open and everything on the desktop gets selected at once! tried using the keyboard to surf the net aswell but it just wouldnt work...i really dont know whats going on with my computer..any help? please!!hidden files dont mean virus.if the antivirus didnt find anything im sure it was fine.should have just chose to format the drive.as for the keyboard and mouse issue try doing a system restore see if it helps.have you restarted system since this started?