Unfortunately, I can not really say why this is happening.
In all my tests, this seems to be pointing out to the fact that the main setup is ran as Administrator.
When I am using the following options, there is an UAC prompt and after clicking OK, the text box appears in the foreground:
Setup "Run as administrator" option enabled from the "Install Parameters", the Custom Action "Launch File" not "Run as Administrator"
I have tried to force my EXE to always run as administrator (as your EXE) to test this, but I did not manage to do much here. I have used the "Run this program as Administrator"
option, but it did not prompt me with the UAC when it was launched by the custom action:
Our developers then modified the exe that is being launced in the Custom Action, so that it does not require administrative rights anymore, I used the same settings as above, there were no UAC prompts and then the text box appears in the background.
This one I did indeed manage to reproduce. In fact, this was the main scenario I was testing:
- "Run as Administrator"
on the main package
- no "Run as Administrator"
option on the custom action
For the moment, I have forwarded this to our development team for further investigations.
I will update this thread as soon as I have any information that might be of help here.