Hi programmer,

my suggestion is to follow these steps:

1) Uninstall the RTDLibraryExcelDemo and make sure to remove everything related
2) Compile the demo source code and then register the dll using the Regasm.exe tool
3) Open the regedit tool and look for the following keys (just search through the whole registry for RTDLibraryExcelDemo.dll)
HKEY_CLASSES_ROOT\CLSID\{2368E0E6-1ED6-3C39-8FAE-45B4A9FB53F3}\InprocServer32\CodeBase
HKEY_CLASSES_ROOT\CLSID\{2368E0E6-1ED6-3C39-8FAE-45B4A9FB53F3}\InprocServer32\1.0.0.0\CodeBase

It's supposed that something has gone wrong with registry settings.
Please get back to us once done for further investigation

Thanks and Regards,
Gianluca