I've made a really big mess, please help!

[Iowan]

It's been awhile...
Try sudo dhclient eth0

[GGG83kf]

Hi frida2, if you are still struggling with this problem, here are something that may help. You can (1) boot into Ubuntu normally, (2) login as a user and connect to internet, (3) logout and press Ctrl+Alt+F1, which should bring you to a console, (4) login and run the suggested commands, (5) logout the console and press Ctrl+Alt+F7 to return to unity.

[frida2]

Ha, actually it hasn't been a while, since I'm not familiar at all with computers - as the fact that I removed Python clearly shows I tried "sudo dhclient eth0", but I only got a message that said "File exists." Any other way to run dhclient from the root shell?

[steeldriver]

Have you gone through the 'Enable networking' boot menu? if so then iirc it sets up a default DHCP connection - I don't recall having to run dhclient manually - you can check the network status with

ifconfig

or more specifically (assuming 'eth0' is the name of the wired interface)

ifconfig eth0

and check that the interface has a valid IPaddress. You can also try a ping test

ping -c4 google.com

If that doesn't time out then you should be good (both connectivity and DNS name resolution are up) in which case you can go ahead and run the apt-get commands

[fantab]

Do you have a 13.04 install DVD/USB with you? If you don't have then perhaps you can download it from somewhere and make yourself a ubuntu DVD/USB.

Do you see a Boot - Menu? If you do then perhaps you can try Recovery Mode, it will be listed under 'Advanced Options' in the menu...
After you've booted into 'Recovery Mode'... follow the instructions here: https://wiki.ubuntu.com/RecoveryMode
This page shows a screen-shot of how 'Recovery mode' interface looks: http://ubuntugenius.wordpress.com/20...recovery-mode/

From Root Shell run the following commands:

apt-get update
apt-get install ubuntu-desktop --reinstall
apt-get dist-upgrade

If you don't have connection to the net then just run:

apt-get install ubuntu-desktop --reinstall

If for some reasong 'apt-get install ubuntu-desktop --reinstall' doesn't work then just use 'apt-get install ubuntu-desktop'

Let us know what happens...

If you haven't cleaned up your 'apt' cache then there is a good probablity that you still have the package 'ubuntu-desktop' in your cache. You can just run 'sudo apt-get install ubuntu-desktop' to install it without networking.
Have you tried it?