Installer built by Inno Setup and SPAWNWND, NOTIFYWND parameters on UAC window

Question

What are SPAWNWND and NOTIFYWND parameters in the program path?

Answer 1

Those two parameters are used for communication between the elevated and non elevated parts of the setup for ...AsOriginalUser functionality, exit codes, etc.
You can probably find more details in the Inno source code itself.

Note that these are an implementation detail and you shouldn't rely on them or do anything with the values.