Registering an .OCX file during setup

Ran into an issue where an ocx file was not being registered during an installation.

I use the standard visual studio setup template and got some some assistance from here: https://social.msdn.microsoft.com/Forums/windows/en-US/a29e664c-a109-4e5f-8b83-e9346ffa529c/register-ocxdll-in-system32-folder-using-setup-wizard?forum=winformssetup

They were right in setting the "Register" property to vsdrfCOM.

However in my situation what was missing was to set the "System" property to True.

This seemed to do the trick.