I have been presented with this situation.
I have a Linux Server (running SuSe 8.2) that has a database on it. However, another company installed it and there are no records of any passwords.
I tried following instructions for using the Suse install disk, and resettign that way, but each time I boot up it has reverted any changes I made. ???
I also tried hitting ESC @ Grub, and entering the text mode. E to edit the line starting 'Kernel' and adding 'single' to the end of it. Upon booting, it still asks for the root password.
There are 4 other users set up on this box, one of which has admin rights.