Force boot into Linux command line

Question

I am trying a number of settings on my Ubuntu 11.10 box. Unfortunately, I messed up some settings and the X window does not boot up.

I need to boot into command line to restore some settings.

However, everytime I boot, the system hangs at the Ubuntu welcome screen. All I can do is to reboot the machine.

Is there anyway I can boot into the command line directly?

Many thanks

Solution

To switch back and forth from X to CLI is by using the virtual terminals. You can boot into X and then hit Ctrl+Alt+<Fn> where Fn is a function key from F2 to F6. To return to X is with Ctrl+Alt+F7