Detecting an MSI "Repair" in an Install class

[Chris Mullins]

I have a Windows Service that I created using Visual Studio.NET 2003. No
custom code, just an empty Windows Service.

In VS.NET, I right click on the service, and say "Add Installer", to create
a custom installer for it inside my project. No custom code, just an empty
installer as generated by VS.NET.

I then create a Deployment project, and set the "custom action" for each of
the steps to run the installer found in the Windows Service project.

This method works perfectly for Install and Uninstall. It fails utterly for
"Repair". The MSI engine, on repair, appears to just call the install step.
The install step then errors out with "The specified service already
exists". How do I fix this?

I was also expecting to be able to go into the install step in the custom
installer and add something to the effect of:
If Repairing then
Do something
else
Do Something Else
end if

.... but I can't figure out how to determine if I'm in the middle of a fresh
install or a Repair.

Any thoughts?

--
Chris Mullins