How do I properly register a OCX?

I have a software which I developed a year ago, that I burned onto a cd.
I started the software and it crashed with an error stating that the certain OCX file is not properly registered or missing.
I checked it's file size and even copy the CD's contenbts into a new folder on my pc but still get the eeror?

This is a reformatted PC, but if all the supporting files are in the EXE's dir, why am I getting the error and how do I rectify it?