How do i get rid of a personal virus protection advertisment?

this program is bugging me about buying there virus protection program. it blocks me from certain sites, wont go away, doesn't give me the option to delete, doesn't give me a number to contact them, and is just annoying! especailly because it wont let me get on any of my normal sites (that have never have given me any trouble). my regular anti virus detection software doesn't detect anything. its called personalvirus. Helppp!