If it's still part of the same "product" (that is, all the exes are being updated at the same time coming from the same wyBuild project file) then you'd be best off using the same GUID in the AutomaticUpdaters.
autmaticupdater guid and multiple exes
In the literature it says about the GUID property for AutomaticUpdater:
Gets the GUID (Globally Unique ID) of the automatic updater. It is recommended you set this value (especially if there is more than one exe for your product).
I have an application that has two executables, i.e the same application code can be started from different executables (both winform projects).
So I have added an automaticupdater control to each of the two winform projests. But the question is:
Do I set a different AutomaticUpdater GUID for each of the projects or the same GUID?
Also when I tested with just the one project having an AutomaticUpdater control everything seem to work including logging of the events. However when I added a AutmoaticUpdater control to the second project I noticed that logging of the events was duplicated as though the events were being fired twice (at exactly the same time).