Remote Task Manager has a nice feature to start a application and choose wether it should be able to interact with the desktop or not.

is there a way to choose that without having to get rtm which costs 40 $ ?

Hidden32.exe, Hiderun.exe for local usage

PSexec.exe for remote usage.

well hidden and hide only hides the windows afaik. rtm doesnt even allow the programm to make a window.

Isn't that what you want? Why would you want to see a window if you can't do anything with it?

Install it as a service (f.e. with firedaemon) and you can set the option, that the application can't interact with user...

can i do this also with ftp.exe e.g. that no one can use it?