If you are dual booting with grub and you forgot you linux root password you can change it like so. Choose linux to boot up and press e on it. On the command line type this. Where new password here is you type whatever password you want.

---

Another way is to boot a linux live cd and mount your linux drive and go to /etc/shadow and delete the password line so the password will be empty. Example of a user in the /etc/shadow file

root:dsfDSDF!s:12581:0:99999:7:::

The password is between the first two : : which is dsfDSDF!s so you will change it to this

root::12581:0:99999:7:::

and save the file

Great code !