Re: Just got laptop & already messed it up... grub>
When I got my System76 it did not come with a username and password, I don't think grahammechinacal is right about that. I suspect Dell would ship just like System76; turn on your computer and the Ubuntu GUI installation is what pops up.
I would guess that you got into the BIOS or UEFI, likely UEFI settings if there is an HDD password. If the computer is brand new and you haven't done anything with it than I strongly suggest you reset the BIOS or UEFI and reinstall Ubuntu.
"Si Dieu n'existait pas, il faudrait l'inventer" -Voltaire