I was going to switch monitors and the screen looked really weird and stretched so I changed the resolution. The next time I turned on my computer and logged in, the screen says it can not display. I switched back to the old monitor. I do not want to reinstall lubuntu, is there a way I can change the resolution back to auto without logging in?
Ctrl + Alt + F1 gives you a command prompt.
Add the following new line using your preferred resolution-depth from the list that vbeinfo gave you. It should be like this if you have a 1280x800 screen:
Save the file and exit. (If you can't save the file you haven't opened it as root, go back and execute gksudo gedit /etc/default/grub providing your password.)
Execute the command
Restart your computer.