How to check if a particual OCX/DLL is registered?

Hi, Greetings everyone..
hope all are fine..

ok. I need a help about how to detect whether a particular ActiveX control (ocx/dll) is registered or not :)

for example:
I have made a software that use flash control. first time I didn't include the flash activex installer (as it's 16+mb in size) but when my client run it.. (windows 7) it's failed to run as flash activex control didn’t found on that system. so, I now add the flash activex install in my software. But the problem is it's makes the installer size huge.

so, what I want to do is:
when my software install on a client PC, it's first check whether flash activex control is available if not only then it will download from my server/website or even from anywhere..

I hope I m clear what I want to mean.. (sorry as English is not my mother tongue)

thanks in advance for upcoming help

best regards