This tweak can be used to disable the popup message that notifies the user that Windows (MSN) Messenger is still running in the background when you close it.

To disable this popup messager, follow the next steps:

1. Open your registry Start -> Run, type "regedit" and click OK.
    
2. Expand HKEY_CURRENT_USER\Software\Microsoft\MessengerService (see picture 1).
   
   

   Picture 1

3. Create a new BINARY value, or modify the existing value, called "DSBkgndMode" and set it according to the value data above.
    
4. The modifications you made will be in effect after you restart or logout you PC.