The IErrorInfo interface has the following methods:
GetDescription retrieves a textual description of the error.
GetGUID retrieves the globally unique identifier (GUID) for the interface that defined the error.
GetHelpContext retrieves the Help context identifier (ID) for the error.
GetHelpFile retrieves the path of the Help file that describes the error.
GetSource retrieves the programmatic identifier (ProgID) for the class or application that returned the error.