Comment 59 for bug 1310489

Hi Abhijit,

don't reinstall Ubuntu!

When your maschine start to boot stop it with ESC to modify the boot option to go into the boot menu.
Enter the first line and push 'e'. This will enable you to modify the boot parameter.
There is a line looking like this:
linux ....... ro quiet splash $vt_handoff....
'....' means that there are some additional commands.
enter before or after 'quiet splash' 'nomodeset' . It should look like below:
linux ....... ro quiet splash nomodeset $vt_handoff....
Reboot now

Another method is to go from boot menu into recover mode and recover the xorg file as described from there.

Even if the x-server doesn't start you should be able to start a terminal again with Ctrl+Alt+F1. Now you are able to recover the old xorg.conf by

1. sudo rm xorg.conf
2. mv xorg.conf.backup xorg.conf
3. reboot

Please try and let me know if you managed to do so.

Best Regards,
Uwe