Ubuntu running on command line due to insufficient graphics

Ubuntu running on command line due to insufficient graphics

my problem is that when i was trying to install nvidia drivers (some 301
version) on ubuntu 13.04,it evokes a message a:"Ubuntu is running on low
graphics". after the installation(i am repenting that installation a lot
:().now whenever i reboot my laptop it show only command line version of
ubuntu 13.04.Though i could have reinstall the Ubuntu using usb-stick,but
it could cost me loss of important data which is stored in home/username/
folder. i tried to copy this folder using live ubuntu through usb-stick
but it is showing that you don't have permissions to copy that. now my
problem could have multiple solutions such as-
1.>i can reinstall nvidia or integrated intel graphics driver so that i
can continue with my previous installation and data.
2.>i can copy the data to an external harddisk through commands (which i
don't know) and reinstall ubuntu(which i know :))
3.>i can copy the data though live ubuntu run through usb-stick to
external hard dissk. problem is i tried many commands on this forum with
similiar problems but none had worked yet.
SO PLEASE HELP ME. your help will be appreciated.