All of the mouse events directed to your application or to any application?
You should be able to catch all mouse clicks for your application using
something like ApplicationEx and an IMessageFilter subclass. See
OpenNETCF.Org for the Smart Device Framework (SDF).
For all windows, even those owned by other applications, there's no way that
I can think of to see all of them easily. You might be able to subclass
every top-level window in the system or something, but windows hooks don't
exist for mouse I/O, unlike keyboard I/O, for which they do, on Windows CE.
It might be easier, if this is a device that you build, to add that
functionality to the mouse driver.
Paul T.