I thought comctl32 was backwards compatable and should not effect anything else even if you had used a newer version of treeview etc. I can see you may need to update a client to the latest version but that shouldn't cause any real grief. Well anymore than making sure they are registered the first time etc.
When you say it then asks for vfp9b files on the clients machine, what files do you mean exactly.
Regards
Regards
Michael Hawksworth