Ubuntu Linux: How to reconfigure X windows system (X.org server)

Q. I had messed up my Ubuntu Linux X windows configuration by editing files. Now all I want is my default settings back to previous state. How do I reconfigure X.org windows system?

A. You need to use dpkg-reconfigure command which reconfigures packages after they have already been installed. Pass it the names of a package or packages to reconfigure. It will ask configuration questions, much like when the package was first installed.

Ubuntu reconfigure xorg

Type any one of the following command to reconfigure X.org windows system:
As the root user:
# dpkg-reconfigure xserver-xorg
OR as a normal user:
$ sudo dpkg-reconfigure xserver-xorg
Just follow on screen questions and you should able to restore or reconfigure to previous state.

See also:

• Black Screen While Starting X window system error and solution