Originally Posted by jschiwal
If booting into single mode doesn't ask for the root password, you can run the "passwd" command.
I think single user mode is the simplest way to resolve password issues, as the root can login without a password, then from there you can reset your root password
while your machine boots, when you see grub press e for edit and arrow down to the kernel line
kernel /vmlinuz-2.x.xx-x ro root=[...]
- press e for edit and then add 'single' to that line, press enter and b to boot
- U're then in single user mode and u can change root password