First of all you need to update your system copy the following command:
when update complete after that you can install the GUI using command line copy the following command:
This command will install the Gnome Desktop on Ubuntu Server Edition. If you want to install graphical interface on Server Edition without all the desktop add-on and other things that come with Ubuntu Desktop Edition, You can install the "minimal" GUI desktop, If you need minimal installation then copy the following command:
When installation complete reboot your pc after reboot you will see the login screen and once you logged in you will see normal looking desktop.
For XFCE (Xubuntu) and KDE (Kubuntu) desktop on related Server Edition. First apply update command and apply following commands:
For XFCE-Xubuntu Server GUI
For KDE-Kubuntu Server GUI