Where are Gnome-Terminal profiles stored in the filesystem?

Profiles for GNOME Terminal are stored in the GConf configuration system. To modify them directly, press Alt+F2 to display the "Run a command" box, enter gconf-editor, and then browse to /apps/gnome-terminal/profiles.

Unchecking /apps/gnome-terminal/profiles/Default/use_custom_command should solve your problem.

An alternative method for getting out of this situation is to override the custom command by specifying another as a command-line argument, e.g. gnome-terminal -x bash, once again in the "Run a command" box.

You can also run xterm, another terminal emulator that is available in Ubuntu. From there you can run any commands you need.

To make it the default terminal, run:

sudo update-alternatives --config x-terminal-emulator

And change the default to whatever you want.

Another approach to fix Gnome Terminal is to use Nautilus (the file manager) to delete all custom preferences:

• Navigate to ~/.gconf/apps/gnome-terminal (it's a hidden folder, hit CTRL+H to view)
• Edit the xml files there, or simply delete the whole gnome-terminal folder
• Open your Gnome Terminal again, it will be restored with factory settings