Only 3/6 speakers working, all worked before

Heys,
Well yesterday i did a virus scan [I use COMODO Antivirus] getting rid of all viruses, my computer was slowing down, there was only one, it was in something like Sound or System Information, so i deleted it and the next day [today] I turned the computer on and i found, out of my Speakers [Logitech X-540's] Only the Front left, Back right and the bass amp were working; does anybody know what i can do?