Thank you for your reply.

I'm running a windows service that detects the existence of an xml file in a directory, if the xml file is there I save the data in the memory, delete the xml file and print the data.

The xml file is generated each now and then by http web requests, so the xml fiile is modified each now and then.

So the Mutex will only be created in Windows Service application ? Can u provide more hints about how to implement on application scope ? I think in my case it would be better if I use Mutex and not System File Watcher as long as my xml file is constantly modified. What do u think?

Thanks again boudino for sharing your knowledge.