This had been asked a few time. Last week actually. Messenger service isn't in the program list. None of the really microsoft stuff is.
to turn off messenger service:
1. Go to My Computer and click Manage.
2. Scroll down to Services and Applications and cascade the menu out.
3. Click Service and look for Messenger.
4. Right-click this option to access its properties.
5. Change Startup Type to Disable.
6. Click Apply and OK.