Yeah, maybe not 100% clean, but deleting something in registry can be very dangerous. Registry is not good place for experiments. There should be list of registry entries, which can be safely deleted or something like manual for removing leftovers by hand if uninstaller is not able doing this. I don’t want delete something only because has Avast in name. Also i will install the same product but newer version, so why more “clean” installation? What is the point here?