Ubuntu :: How To Edit In A Command Prompt

i somehow managed to mess up my install of 10.10 I used the alternate AMD 64 install so now when I login it is only a text prompt. This leads me to believe that I am running in Ubuntu Server. I read this article:

[URL] but my network is not setup!! So I tried to do this: [URL] but when I get to:

Code:

sudo vi /etc/network/interfaces

I dont realy know how to edit the file.I basicaly see

Code:

# The loopback network interface
auto lo
iface lo inet loopback

[code]....