Re: Registering ocx on Vista
Clearly they aren't "installing" the application or this problem doesn't arise. Are you just copying files and calling this an installer?
Either the PDW that comes with VB6 or the Visual Studio Installer 1.1 (free) add-on for VB6 are good basic choices for application packaging. In both cases the user still requires administrator rights to install though and will see a UAC prompt.
Re: Registering ocx on Vista
I am going to do the same thing sometime down the road. I purchased an installer that i think will do what you need here:
http://www.gdgsoft.com/pb/index.aspx
I looked at a lot of installers see here: http://www.vbforums.com/showthread.php?t=515296