You should run the AVG uninstaller, you can find it here http://singularlabs.com/uninstallers/security-software/
You should also uninstall Threatfire as running two resident anti-virus programs can and will create conflicts.
Having two a/v’s is just asking for trouble. See http://www.bleepingcomputer.com/forums/t/260844/two-anti-virus/#entry1441638
Then do a clean install of avast. :slight_smile: