Can anyone help me get samba working again?

I can see that it's installed but running a variety of commands all throw up errors.

Code:
sudo service samba4 start
samba4: unrecognized service

Code:
sudo  update-rc.d samba defaults
update-rc.d: /etc/init.d/samba: file does not exist
Code:
 sudo /etc/init.d/samba status
sudo: /etc/init.d/samba: command not found
I've reinstalled samba but nothing changes.

I'm running 12.04