Thanks for the input Sanjay. That makes it clearer still. Problem is, they're not my DLL's or OCX's. They came with another application -- DynaZip to be specific. I was hoping that maybe I could determine whether an OCX or DLL was SELF REGISTERING and SHARED by looking at controls themselved, or (b) the vendors documentation (ha, ha).

It's been trial and error. One particularly maddening component was MSACAL70.OCX (Microsoft Access Calendar Control) which I use to display a calendar from which a user can pick a date. InstallShield often crashes violently when it tries to install that component and haven't been able to figure out why. (Even the InstallShield people looked at my project to no avail -- the crash sometimes did and sometimes didn't happen. Grrrrrrr...)

I appreciate your insight and thank you for your time.

Ernie