Cetin,

What about the possiblity of creating an init.exe to download the current version of the Main.app (by comparing modification datetime) and then running the main app at the end of the init? I've used this technique to also download any updated references tables which also should reside on the client machine.

This way you can make modifications to the main application while people are using the system and they get the most current version when they leave and reenter the system.

It has worked well for me but I don't know if there are potential problems doing this.