Preventing multiple instances of .Net Application

Single instance application in VB.Net

If you were creating a Windows application, most often you would be doing some database initialization or some network validation before you show up the form to the user.

The patient user might wait few seconds to let the form show, others might launch the application again. To avoid user launch multiple instances of the application, select the Make single instance application check box to prevent users from running multiple instances of your application. The default setting for this check box is cleared, allowing multiple instances of the application to be run.

You can do this from ProjectàPropertiesàApplication tab