Cant Remove Torrentfile From Desktop I Cant Remove Avast Antivirus Nor Can I Add Another,why?

I cant remove avast antivirus nor can i add another,why? - cant remove torrentfile from desktop

I want to delete a computer virus Avast and AVG, or add others one.But Avast says that does not work and I can not re-enable it and theres an X in the icon? Attempts to delete them, no!
Now I can not install, AVG says theres failure.Im guess because Avast is there?
Please help!