That error message means the application attempting to use the Oracle Provider for OLE DB failed as the provider is not installed, i.e Class is not registered. This can happen on x64 for the following reasons.
Your application is running as a 64-bit application and the 64-bit Oracle Provider for OLE DB is not installed or registered.
Your application is running as a 32-bit application and the 32-bit Oracle Provider for OLE DB is not installed or registered.
The classes are registered on different parts of the registry on x64. 32-bit providers will be under syswow64 node in the registry.
The steps to fix this are generally:
- If you're running a 32 bit app, install the 32 bit client and provider.
- If you're running a 64 bit app, install the 64 bit client and provider.
Hope it helps
@greg: hi, thanks for your advise. i was able to resolve the connection problem of my excel apps 32-bit to connect to oracle on windows 7 64-bit os.
i install the 32-bit oracle client from this download .