instant root shell to change that pesky forgotten root password via grub

forget knoppix. just do it natively. oh, this only works if grub's not passworded. usually isn't.

* press esc at the grub prompt
* highlight the line that begins with kernel XXX , press e
* go to the very end of the line, add rw init=/bin/bash
note:  that is if bash is in /bin ; if not try /usr/bin or /usr/local/bin
* press enter, then press b to boot system
note:  system should now boot as root shell sans password.
* type passwd username.  set password.
* type reboot