title: When To Change a GUID on a Type Library
body: <p>I know that when you add/change/remove methods in a COM interface you're supposed to change the interface/coclass GUID but what about type libraries.  When should you change the type library's GUID? Do you change it if a GUID inside the type library has changed? Or should you only change it when something that doesn't have its own GUID within the type library changes.</p>