Can you exactly tell me what are those left overs?
I've deleted the keys into the registry and does not write them down. Sorry.
They were here:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
and
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_ ...
Take care about what you're deleting from registry!
In the subkeys will be clearly identified that the drivers are from AVGas or AVG antirootkit.
You need the have permissions (access) to the key. Start deleting the subkeys, one by one and you'll be able to delete the major key.
Take care handling the registry, as usual.