Due to the fact that you can't get past the login screen, these instructions
must be followed on a virtual terminal, just choose one of the six available
ones by pressing Ctrl + Alt + (F1 through F6).
After chosing a virtual terminal, it'll ask for your username and password.
After entering the right informations, the virtual terminal will be available
for you to use, and so allowing you to continue following these instructions.
We're going to stop GNOME Display Manager (which interacts with Xorg X
Server), see if you have a file called exactly xorg.conf, and if so, we'll
make a copy of it and remove the original file (leaving the copy untouched),
and then we'll start GNOME Display Manager again.
After every newline in this comment, just press Enter in the virtual
terminal. Don't write the texts between the hash symbols (#), they'll just
explain what we'll do.
# As superuser (administrator), this stops GNOME Display Manager (GDM). This
will ask for your password. #
sudo service gdm stop
# Opens the folder X11, which is inside the folder etc, which is at the root
of the filesystem (/). #
cd "/etc/X11"
# Checks if a file named exactly as xorg.conf exists. If the file doesn't
exist, you don't need to follow these instructions any further. #
ls "xorg.conf"
# As superuser, this makes a copy of the xorg.conf file, and renames this
copy to xorg.conf.1. #
sudo cp "xorg.conf" "xorg.conf.1"
# As superuser, this removes the original file. #
sudo rm "xorg.conf"
# As superuser, this starts GDM again. #
sudo service gdm start
Now press Ctrl + Alt + F7 and see if you can get past the login screen. If
the problem got worse, go to the previously chosen virtual terminal and
follow these instructions to revert the past ones:
# As superuser (administrator), this stops GNOME Display Manager (GDM). This
will ask for your password. #
sudo service gdm stop
# Opens the folder X11, which is inside the folder etc, which is at the root
of the filesystem (/). #
cd "/etc/X11"
# As superuser, this makes a copy of the xorg.conf.1 file, and renames this
copy to xorg.conf. #
sudo cp "xorg.conf.1" "xorg.conf"
# As superuser, this starts GDM again. #
sudo service gdm start
Best regards, ADFENO.
Have a nice day.
