What causes the Vista/Win7 warning: "This program may not have installed correctly" ?

Question

What causes this warning and what can I do to keep it from popping up when my app installs?

Possible causes:

• Virus scanning software (I'm looking into that)
• Not putting the uninstall in the Add/Remove programs (this will definitely cause the problem, per documentation from Microsoft (see answer below)
• Putting .ocx or .dll files in the App Directory?
• Not registering the library files (app runs fine without reinstalling, so I don't think this is it.

Any other ideas?

Answer 1

To fix this, see this blog post by Aaron Stebner:

• Your app is probably being detected by the PCA (Program Compatibility Assistant) as a non-Vista (pre-Vista) installation application.
• You will need to add an embedded manifest and set a requested execution level

There is a previous stack question on this topic as well with some alternative work-arounds (noob, I can only post one link at the moment). You should be able to find some information on Vista-aware installation applications and be able to resolve this issue, but the info above has worked for me in the past.

Answer 2

One of the reasons this pops up is that after running the installer, the system checks to see if something changed in the installed programs list. If the contents of the installed programs list hasn't changed, it assumes that your application failed to install correctly.