>Hi,
>
>You have a few options that can achieve this.
>
>1. Use the CreateMutex Function API
>2. Create a temporary user specific local file and keep a handle to throughout the duration of the application. If the user tries to create a second instance you can detect the undeletable version of this file and stop the application opening. If the app crashes, your file can be deleted.
>3. Use George Taskers Is_Run available in the downloads. If this uses getwindowtext, I am not sure.

You ignored my ClsEvent class, which can manage a single-instance -anything- within a single machine - it permits named event objects, so that several single-instance event monitors can be running independently at the same time on a single system...