I have set up individual major upgrade items for every version that may get upgraded to the current one in a basic MSI project that we recently upgraded from IS 12 to IS 2009 sp2. The upgrade seems to be picking up the old version and uninstalling it correctly before installing the latest version. I've checked ARP, windows assembly, etc.... the old version seems to have been cleaned out properly.
Here's the problem: In several tests on different machines and VMs running Windows XP (haven't checked Vista yet), every time one of our executables is run I get a message that is coming from msiexec (our exe seems to launch the windows installer service (and thus msiexec.exe) -- I've stopped the service and tried again to verify this) -- the message is designed to abort an install if an unidentified version is detected. This would be the correct behavior IF I tried installing the same latest version again, since I don't recognize the current version as a version which we allow upgrading yet. In some cases it is just an annoyance... you click OK twice (the box comes up twice for some reason) and then the app runs. However, in the case of our main application the app crashes (could be an unrelated issue, but i doubt it).
I assume there must be some sort of hook in registry tying our product to msiexec after doing the major upgrade. I've checked to make sure our dlls are registered correctly, and there are no old versions lying around, but I'm not sure what to look for with regards to msiexec. It would be great if I could learn how to "cut" this cord.
One further note -- we have seen this both on machines with the MSI 4.5 hotfix (KB942288), and without (just running MSI 3.1). We upgraded to .NET 3.5 sp1, as our latest software requires it.
Note also that this problem was seen BOTH after upgrading a previous basic MSI version and upgrading a previous Installscript MSI version (with the same dlls, etc.).
