Have you tried running something like Cccleaner - then trying to install?
Have you checked out msinfo32?
If you've removed all directories and registry keys, then a driver must still exist.
I see the avg drivers but don't know how to uninstall them. How do you.
Find this registry key, delete it and then restart your system
HKEY_LOCAL_MACHINE\SYSTEM\\CurrentControlSet\\Services\\AvgClean
You can use regedit to modify the registry: http://en.wikipedia.org/wiki/Windows_Registry