In case of emergency, you can recover your root password by following these steps: (Mostly for RHEL4/Fedora/CentOS-based Linux systems)
- Power on the machine/reboot if necessary
- On the boot menu, select the OS you preferred and press `e` on you keyboard
- Select the image you would like to boot, and press `e` again as soon as you get to the next screen
- Insert a space and the number one `1`. After that press ENTER and `b` and ENTER again
- You have now your system booted in a single user mode without entering a password
- Type on the shell ‘passwd’ and enter your new password
