When I am trying to launch external application on the asp.net server, I see that the process is executed and it works fine, but everything runs in background mode.
I am using cassini web server. Also StartInfo.CreateNoWindow = false; does not help.
For example Visual Studio Development server shows everything fine.
How can I launch an app and see it running visibly?
This is expected and correct behavior. ASP.Net/IIS run as a service, and any windows created by a service are shown on a private hidden desktop reserved for that purpose. There is no way to show this desktop.
It works in the development server because the development server is a normal app running within the context of your normal user desktop.
If you want the window to open on the user’s computer with their browser, this is just not possible.