My PC got infected with a worm as I had left the windows firewall turned off.I have a version of AVG which can just detect the PC for viruses.In order to remove them i require the license key which unfortunately i cannot find in my setup folder.I tried uninstalling AVG in order to install Kaspersky but the worm/virus doesn't allow any program to run.Is there any other way i can disinfect my PC apart from formatting windows?