See Re: Only open application once Thread #585701 Message #585856 and file #9807 Implementation of the Win32 Event object.

>How can I prevent a user from opening an application a second time? Never had the problem before, but seems like it all of a sudden became a problem with one of my clients. I searched both the download files and other thread and never found the right keywords as I remember it coming up several times before. I've toyed around with creating a memory variable,then wiping it out when they exit, but not sure how to deal with a computer crash or system lockup.
>
>Any help appreciated
>Gaylen