Recently I was trying to update AVG 8.0, but it kept saying Invalid Update Control CTF File. Well, there’s nothing much to fix this. Navigate to “C:\documents and settings\all users\application data\avg8\update\download\”. Here, rename the two ctf files avginfowin.ctf and avginfoavi.ctf to avginfoavi.ctf_old and avginfowin.ctf_old or delete them. Now, right-click avg 8.0 icon and click update. It should update this time.