Here's what I'm after, I have 3 versions of the application and what I want to do is the following:
1) if any version in installed and there is no previous version, run it just like a clean install
2) if any previous version is found, ask whether to run that version's uninstallation routine and if the user answers yes take the following actions prior to file copying:
>>> Backup all the previous version's files just in case the user wants to roll back
>>> run the uninstaller
3) if the user answers no, then do an in-place upgrade and replace the items in start and the entry in add/remove programs.

I've set all my versions to the same "upgrade GUID" and still wind up with 3 versions in add/remove in control panel and none of them remove.

Thanks for any help given on this one :-)