I couldn't get rid of Altnet in the registry until I right clicked on the key and found a way to change permissions.
i.e. "take ownership", which finally did the trick.
Before that I tried many things including:
Removing Kazza, which is where it came from.
Deleting directories called Altnet. Bullguard.
Deleting other registry keys to
do with Altnet, P2P, Bullguard.
Emptying all temporary directories.
Adaware now runs clean for me.