No offense - really - but, why You installed something like fAircrack, while you don't have a clue how terminal work? Wasn't it more sane, to learn basics things first, then *eventually* try penetration testing software?

This time it was trivial. Next time, You may mess something up seriously.

I'm not writing this to discourage anyone - just, please, do backups (using backupmenu, preferably), and don't execute code that You don't understand, at least on same basic level.

/Estel