One of our products has an install set up as mixed, so it will default to per-user for non-admin users and all--user for admin users. Lately, I have been getting hammered by issues where a machine ends up with BOTH a per-user and all users install on the same machine with different versions. A typical scenario is an IT person will install the software. Since they are admins it defaults to All Users and gets installed that way. Then a user wants to update to a later version. Since they are NOT admins, they get a per-user install. The machine is left with two installs with two different versions and only one of them will work.
What I would like to do is either force the user to do the same install as the previous install OR at least warn them before continuing. I think I can do that via custom actions by saving AI_INSTALLPERUSER in a file or the registry, then checking against that saved value on the next install. But it seems like a clumsy and roundabout way to go. Is there a simpler solution I am just missing?
Thanks!