The module ".dll" was loaded but the entry-point was not found
I had this problem and
dumpbin /exports mydll.dlland
depends mydll.dllshowed 'DllRegisterServer'.
The problem was that there was another DLL in the system that had the same name.After renaming mydll the registration succeeded.
The error indicates that the DLL is either not a COM DLL or it's corrupt. If it's not a COM DLL and not being used as a COM DLL by an application then there is no need to register it.
From what you say in your question (the service is not registered) it seems that we are talking about a service not correctly installed. I will try to reinstall the application.
What solved it for me was using :
regasm.exe 'xx.dll' /tlb /codebase /register
It is however, important to understand the difference between regasm.exe and regsvr.exe:
What is difference between RegAsm.exe and regsvr32? How to generate a tlb file using regsvr32?