COM dll registration failure

Every shop has at least one legacy piece of software they have to support. Written in VB6. With lots of copy/paste code and sections that may or may not still be active. By a developer long since gone from the company. It's bad enough to have to deal with the code itself, but try and rebuild the equally-convoluted installer and you might just go mad.

Our problem wasn't in rebuilding the installer, per-se, but in getting it to run successfully afterward. One issue we ran into were COM dlls that failed to self register.


When we attempted to run regsvr32 on this particular dll, we were given an error dialog stating:

LoadLibrary("C:\WINDOWS\system32\pcmcom.dll") failed - The specified module could not be found.

This particular issue is often due to a missing dependency. To verify this we opened up Dependency Walker and loaded pcmcom.dll. In the screenshot below, you can see the yellow question mark symbol next to pcm.dll - our missing dependency. Once we found pcm.dll and its dependencies, pcmcom.dll registered without issue.