If you’d like to disable webgui mode of Debian wheey, run the commands in the terminal as root-
update-rc.d -f gdm remove update-rc.d -f gdm3 remove update-rc.d -f wdm remove
Disabling graphical (GUI) login in Debian wheezy/7
Brain's Workbench
If you’d like to disable webgui mode of Debian wheey, run the commands in the terminal as root-
update-rc.d -f gdm remove update-rc.d -f gdm3 remove update-rc.d -f wdm remove