The IUserEventTimerCallback interface is to be implemented by a user of the IUserEventTimer interface who has specified that expiry of a user event timer be notified through a callback function instead of by posting a message to a window.

IID_IUserEventTimerCallback {E9EAD8E6-2A25-410E-9B58-A9FBEF1DD1A2}

There is just the one IUserEventTimerCallback method beyond the three IUnknown methods:

Offset Method
0x0C UserEventTimerProc

No implementation of this interface is known.


The IUserEventTimerCallback interface is supported by SHELL32.DLL version 6.00 and higher.

The interface seems never to have been documented, but is declared in the SHOBJIDL.IDL (and thus also SHOBJIDL.H) from the Platform SDK dated February 2003. This declaration may have been an oversight: it is removed from the Windows Vista SDK dated January 2007.