1) Stop the Bonjour Service as follows:
Start > Run
Type services.msc
Click 'OK'
Double-click the Bonjour Service.
Click on the 'Stop' button & next to Startup Type set it to Disabled.
Then click 'OK'
Restart Windows.
When Windows is back up, you should be able to delete mdns.responder & any other files sharing that folder.
Then delete the Bonjour folder itself.