When I try to log on to AVG or Gfi or anysite for an antivirus program the bowser shows unable locate browser. All other sites work fine

You probably already have a virus. That's one of the signals that tip off users. Many viruses will block access to programs or websites that would allow you to remove them or block them. If you have antivirus software, run a full scan. If you can't get the program to run, then you're going to need professional help.