Recover GNU/Linux root password.

What's happening if you forget root password on your GNU/Linux system? You could reformat your hard-drive and then install OS and software, or you can start your system in single user mode.

Some distributions like Ubuntu, inside menu which you can call while you startup your system, offer Recovery Mode or Single-User mode. If you have this kind of problem it is enough that you choose this item and fallow next steps. Otherwise you need to add this item inside menu (which could be called by pressing on ESC button on keyboard). Using arrows on keyboard choose menu which you want to change, press button E on keyboard and again use arrows on keyboard to choose kernel line and again press E. Now at the end of this line add word "single".

Now you need to press ESC to go back and then use button B to load this kernel. Your System will startup as usual, but maybe with command prompt. To change password all you need to do is to type command "password" and you will be asked to add your new password (you need to insert this password two time, just for security reasons), while older password is not necessary.