When your application starts try to open an DDE channel to your application. If you are able to open the channel the application is already running, if you are not able to open the connection then the application is not running and you need to start your DDE server. You can also add code to activate the first occurance of the application if you are able to open the channel. This means that when the user runs the application for the second time it will not run but the first occurance of the application will be activated.

HTH,
Shane

>How can I make sure that a program is not all ready running on startup?