I just went through this not long ago!!! It played games with my computer that almost sent me crazy! Called my cable company and got connected with the Anti-virus supplier. I have Comcast, so they connected me with Norton and I don't remember what we did, but it was a pretty easy fix. See if your cable company can assist you with this. I thought I was losing everything!!! Couldn't access stuff, very frustrating!!! Norton did assist me with this though.
Good Luck!!!