As this question merged to here, there is need to provide some information which may helpful
From man apt-get
:
remove
remove is identical to install except that packages are removed instead of installed. Note
that removing a package leaves its configuration files on the system. If a plus sign is
appended to the package name (with no intervening space), the identified package will be
installed instead of removed.
purge
purge is identical to remove except that packages are removed and purged (any configuration
files are deleted too).
So, when you remove package(s) usually by using Ubuntu-Software-Center or by sudo apt-get remove
, it leaves its configuration files on system.
From community help,
While there is no built in way to remove all of your configuration information from your removed packages you can remove all configuration data from every removed package with the following command.
dpkg -l | grep '^rc' | awk '{print $2}' | xargs dpkg --purge
So, Run following command from terminal:
dpkg -l | grep '^rc' | awk '{print $2}' | sudo xargs dpkg --purge
This will removes configuration files from removed package.