Unknown User Types
You can ease product localization by adding the following registry key:
HKEY_LOCAL_MACHINES\SOFTWARE\Microsoft\OLE2\UnknownUserType = usertype
This key allows functions to return a specified string rather than a default value of "Unknown", enabling localizers to specify a user type of a different language.
The COM default handler's implementation of IOleObject::GetUserType examines the registry by calling OleRegGetUserType. If the object's class is not found in the registry, the user type from the object's IStorage instance is returned. If the class is not found in the object's IStorage instance, the string "Unknown" is returned.