I have recently installed Ubuntu 12.04 alongside Windows 7 and was having trouble changing brightness. However, I found what was apparently a solution, it involved changing a directory I cannot remember sorry, however now Ubuntu crashes at the logo when starting up. I am unsure how to navigate recovery mode to get back and delete my changes, any help would be appreciated.
[Edit] Now when booting it only displays in text, Windows 7 boots fine however, just need to undo my error it seems but unsure how to navigate back to this file.