So you messed up the Gnome desktop and don’t know how to restore it back to it’s default settings. Here’s how with no risks.
1. Log out and then hit “Ctrl + ALT + F1” to opening up a terminal.
2. Delete the following directories.
.gnome .gnome2 .gconf .gconfd .metacity
Or run the this command.
rm -rf rm -rf .gnome .gnome2 .gconf .gconfd .metacity
3. “Ctrl + ALT + F7/F8” and log in as usual.
This guide is based on Ubuntu 10.10