the DDE method looks fairly straightforward/simple compared to the mutex article refered by George Tasker. Unfortunately, the machines expected torun this application are notoriously unstable. The DDE method requires some shut-down code, which may not get a chance to run. If a disconnected flag could prevent a 'recovered' windows system from running the application, then it'll introduce new headaches...

I'm going to try the mutex example, and hope i can make sense of the API calls since i've never used them before. Most likely, i'll be back for more help. :)