When I was updating AVG Anti-Virus 8.0, i got a error "Invalid Update Control CTF File".
It is a easy way to resolve the error for AVG Anti-Virus.
1.Open the AVG Anti-Virus 8.0 and click the Tools menu --> Advanced Settings --> Manage option.
2.Then Click the " Delete temporary update files" button and confirm removal by clicking Yes button.
Now you can update AVG with any error.