[wix-users] Elevated CA before GUI?

[Persson, Magnus (SE-TLX)]

I need to call a CustomAction before the GUI part is shown to check if 
services or processes that are part of our software suite is running and 
if so, tell the user to terminate the running application and restart 
the installer when done.

The problem is that the 'process snapshot' APIs do require elevated 
rights and I do not know how to do that in the InstallUISequence.

I use the CA to set conditional properties that will trigger the error 
message so running the CA as deferred will be too late for that.

Any ideas how to solve it in a better way?