>Hi All,
>I have one EXE which is on my server. i have four client machine.
>
>But i want to run this exe by one client only. when the Exe is running from one client then no other client can run this exe.
>So what code i include in this.
>

You might investigate creating a shared synchronization object visisble in the network environment such as a named pipe or mailslot; before starting the app, check to see if the object exists, and if it doesn, don't start the app. If it doesn't exists, create it before starting the app to prevent others from starting the app until you're done. Mailslots in particular are relatively easy; they go away when the mailslot server shuts down.

No, I don't have code to give you to do this; try reading the entries in the MSDN library regarding synchronization objects, and mailslots in particular.