regsvr32 C:\Windows\System32\mscomctl.ocx DllRegisterServer in mscomctl.ocx succeeded. Step 4: Troubleshooting common errors | Error | Solution | |-------|----------| | "Module failed to load" | Run CMD as Administrator. Check file path exists. | | "DllRegisterServer entry point not found" | File is corrupted or wrong version (try the redistributable). | | "The module was loaded but the call to DllRegisterServer failed" | You likely have a 64/32-bit mismatch. Use SysWOW64 for 32-bit OCX on 64-bit OS. | | "Access denied" | UAC blocked registration – ensure admin CMD. | Step 5: Alternative – Silent/automated registration (for IT deployment) Batch script example:
If you put it in System32 on a 64-bit OS, the 32-bit application will not see it. Step 3: Register the OCX (Run as Administrator) Open Command Prompt as Administrator . For 32-bit Windows (or 64-bit + SysWOW64 path): regsvr32 C:\Windows\SysWOW64\mscomctl.ocx For 64-bit Windows with file in System32 (incorrect for 32-bit apps): (Generally avoid this) mscomctl.ocx download