Re: single task windows

Might help if you told us what language you're programming in.  Why on earth you want to have such a lockdown I'll never know but you could make your app system modal.  Restricting users is easy.. have a login screen and if they can't login they can't run the app.  You say you want to replace your program with explorer.. I don't understand.

i want to prevent users of  my program from running any other progrem in windows nt. in the other hand , i want to replace my program with explorer and restrict users in my program. is it possible? how can i do this?

my applicatin works in a financial organization and containes many files and rules thereby i want to become users as restricted as possible for avoiding undesirable events.

I can understand wanting to restrict users abilities within the application.. I do that all the time.  Have the user log in and based on the login they have access to certain areas/functions.  Again.. what language are you writing your code in?  I think, to prevent a user from using ANY other software, you'll have to go with a 3rd party application like zenworks on a Novell network.  You will find it very difficult if not impossible to prevent users from using something other than your app.