So I've got a Dell XPS 15 for my work laptop and being a dev, I obviously prefer Ubuntu to Windows, however I've recently run into problems with Ubuntu in booting.
I was trying to figure out, what are all the things I've installed on this which could be preventing me from booting... I also have encryption setup as it's a work laptop.
To get to recovery mode, after the manufacturer logo press
esc once! then choose recovery mode in the boot loader.
When you're in recovery mode, select root, this will dump you into a root console terminal.
I could not figure out what was wrong, luckily I had access to GRUB, so was able to get into recovery mode, and just ran the following;
sudo dpkg-reconfigure lightdm
When the Window showed up, it gave me 2 options,
gdm, I chose lightdm, which was the default, in doing this, just rebooted the machine and it booted!
Hopefully this randomly written article will help someone! I just happen to always post about issues I have and how I resolved them in the hopes it helps others ^_^