Base-config - Debian base system configuration
base-config this package handles setting up the Debian base system. It contains the configuration program you see when you install Debian for the first time and boot up your new Debian system.
It can be removed with no ill effects -- once your Debian system is installed, this package's only useful function is to allow you to reconfigure some things.
Install base-config in Debain
#apt-get install base-config
Run from your command prompt
This will give you the following options to reconfigure
Set up users and passwords
Set the hostname
Select and install packages
Configure the Mail Transfer Agent
Finish configuring the base system
Execute a shell
You can choose which one you want to configure this is very useful when you want to reconfigure any of the above services
If you want to know more about this check man page of base-config