When you try and connect to HP ALM 11 using the Spira Importer for HP QC 9.0+ you may receive the following error message:
System.Runtime.InteropServices.COMException (0x80040154): Retrieving the COM class factory for component with CLSID {C5CBD7B2-490C-45F5-8C40-B8C3D108E6D7} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).
This article describes the steps necessary to resolve this issue.