Gnome is a default and user-friendly desktop for Linux based systems. Sometime you can encounter such errors that your Gnome Desktop becomes unresponsive. Usually people reboot the system to make it work again. Let me share some tips to get your Gnome refreshed without rebooting the system.
Save all your open files and press Ctrl–Alt–Backspace. It will restart the Gnome instantly in almost no time.
If the above shortcut keys does not works for you then open your terminal (Applications > Accesseries > Terminal) and run following command. It will also restart it.
sudo /etc/init.d/gdm restart
Open terminal and run following command.
That’s all. Its pretty easy to restart frozen Gnome with any of the above methods. Enjoy!