changing resolution without screen

[Vincent Trouilliez]

> But as my screen shut off I dont know how to get to the
> command-line. Furthermore, this happened during installation and I don't
> know how much more configuration there was to do. Being a first-timer, I
> don't know what to expect.

Don't worry, looks like the problem happens when X tried to start, that
is, when Ubuntu tired to start GDM to let you first log-in into Ubuntu.
so I think the installation process was 100% finished. 
So GRUB etc should be installed. Just restart your machine and in the
multi-boot menu, choose "Recovery mode". This will give you the command
line/prompt, as root. From there you can do whatever you want to.
Go to /etc/X11, the configuration file for the X server is the one
called XF86Config-4.  You can open it with nano (easier than vi, if you
are a newbie). 

HTH,

Vince