sudo service lightdm stop  

 sudo vi /etc/default/grub  

 # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_TIMEOUT_STYLE=hidden GRUB_TIMEOUT=0 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" GRUB_CMDLINE_LINUX="" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1"  

 #GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"  

 GRUB_CMDLINE_LINUX="text"  

 GRUB_TERMINAL=console  

 sudo update-grub  

 sudo systemctl set-default multi-user.target  

 reboot  

 sudo systemctl set-default graphical.target  

 sudo vi /etc/default/grub  

 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"  

 GRUB_CMDLINE_LINUX=""  

 #GRUB_TERMINAL=console  

 sudo update-grub  

 reboot