PRB: Error: "Failed to Get Expression Service"

The information in this article applies to:

• Microsoft Open Database Connectivity, versions 2.1x

SYMPTOMS

Installation of ODBC 16-bit components with incompatible versions of OLE DLLs causes the error "Failed to get expression service."

The installation of ODBC 2.1x SDK on a fresh installation of Windows 95 also causes the error message described above.

The following table shows the difference in version numbers of the OLE DLLs that cause this problem.

                               Version installed with
File name         Windows 95         Windows NT         ODBC 2.1x SDK

Compobj.dll          2.2               2.1                  2.02
Ole2.dll             2.2               2.1                  2.02
Ole2conv.dll         2.01              2.1                  2.01
Ole2disp.dll         2.1               N/A                  2.02
Ole2nls.dll          2.1               2.1                  2.02
Stdole.tlb           2.1               2.1                  4.2kb (has no
                                                         internal version)
Storage.dll          2.2               2.1                  2.02
Typelib.dll          2.1               2.1                  2.02

WORKAROUND

To work around this problem on a computer running Windows 95, delete the existing files mentioned above in the <Windows 95 root>/System directory and reinstall the ODBC 2.1x SDK. Make sure that the files have the correct version numbers after the ODBC 2.1x SDK reinstallation.

MORE INFORMATION

On computers running Windows NT 4.0, this does not cause a problem because the versions of the above files later than 2.02 are the 16/32 interoperability OLE DLLs (32-bit), and are installed in the <Windows NT root>/System32 directory. A fresh installation of the 16-bit ODBC components from the ODBC 2.1x SDK are installed into the <Windows NT root>/System directory.