1. $ sudo apt remove update-manager
  2. [sudo] password for user:
  3. Reading package lists... Done
  4. Building dependency tree
  5. Reading state information... Done
  6. The following packages will be REMOVED:
  7. ubuntu-desktop ubuntu-release-upgrader-gtk update-manager update-notifier
  8. 0 upgraded, 0 newly installed, 4 to remove and 7 not upgraded.
  9. After this operation, 1,501 kB disk space will be freed.
  10. Do you want to continue? [Y/n] n
  11. Abort.
  13. $ sudo apt remove update-notifier
  14. Reading package lists... Done
  15. Building dependency tree
  16. Reading state information... Done
  17. The following packages will be REMOVED:
  18. ubuntu-desktop ubuntu-release-upgrader-gtk update-manager update-notifier
  19. 0 upgraded, 0 newly installed, 4 to remove and 7 not upgraded.
  20. After this operation, 1,501 kB disk space will be freed.
  21. Do you want to continue? [Y/n] n
  22. Abort.

http://askubuntu.com/questions/218755/how-to-disable-the-update-manager-popup