Maybe some of your customized settings are causing your gnome-panel to crash all the time or causing your windows and applications to look ugly, even having window buttons (close, minimize) disappear. You start Googling and spending a lot of time - sometimes days - trying to find how you can fix it.
You are frustrated (sometimes hitting your monitor/tower yelling some vulgarities at it as if it understands and you will kill it if it doesn’t fix it… there’s no Valentine’s love there, that’s for sure) and are ready to go back to Microsoft Windows.
You keep thinking, “I wish I could just reset it back to its defaults, like a clean install, without losing all my applications and data.”
Well, you’re in luck. There is a way to reset your Desktop settings back to their defaults. If you keep in mind that everything in Linux is a file, all of its settings are files. All of Gnome’s customizations are located in their own specific folders. And these settings are user specific; they are in your Home folder. If you would create another user and log in with that user, you wouldn’t have any of the problems you are having in your own account. If you remove all these folders, you essentially remove all the settings. Therefore, we will remove the folders needed to reset Ubuntu/Gnome back to its defaults.
UPDATE (): Keep in mind that this will only reset your Gnome-specific settings. If you are having problems with your video card, display, x-server, etc., this WILL NOT fix your problems.
If you don’t have access to your graphical (GUI) desktop to delete these folders in Nautilus or you’re stuck at the login screen, drop to a terminal by hitting CTRL + ALT + F1, login to your account, and run this command:
rm -rf .gnome .gnome2 .gconf .gconfd .metacity
Get back to your GUI desktop by hitting CTRL + ALT + F7.
Login and VOILÀ! Just like the first time you ever logged into your Gnome desktop.