The article at this link may help resolve this issue.
Error Message When You Run Regsvr32.exe on 64-Bit Windows[
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The article says to do the following to register a 32-bit DLL on Windows 8.
cd \windows\syswow64
regsvr32 c:\filename.dll
It is not very intuitive but the regsvr32.exe in C:\Windows\System32 is for 64-bit DLLs and the regsvr32.exe in C:\Windows\syswow64 is for 32-bit DLLs.