RCCONF is a TUI (text user interface) utility that lets you configure the services and daemons that are launched at system start-up.
When you install it on Ubuntu 12.04 / 12.10 and then launch, it returns the following error:
"rcconf needs dialog or whiptail"
Dialog and whiptail are utilities to display user-friendly dialog boxes from shell scripts. Despite the fact that whiptail comes preinstalled with the system, rcconf doesn't run.
sudo apt-get install dialog
Now launch a terminal, and run rcconf.
Whiptail is already there, but not in the folder the apps try to launch it from (see the comment by Viajemotu below). All you need to do is to create a symlink to the app in the /usr/bin directory. To do so, execute:
$ sudo ln -s /bin/whiptail /usr/bin/whiptail
After this, run rcconf.