Hello geeks,
so i wanted to learn "how to break ubuntu's password". i boot the machine with a live cd, then deleted the user password in "/etc/shadow", after rebooting, i couldn't log into the system graphically, although i could log via the tty1,..(using crtl+alt+f2,..). then out of curiosity i deleted the user from "/etc/shadow" file, now neither can i create an account with the previous account name,nor i can delete it,whenever i try to delete it, it returns with "error code 1",(i also can't login with that account via tty,)so what should i do? any help is appreciated.

tanx

You can remove the user by deleting the user's lines in both /etc/passwd and /etc/shadow

You'll probably also want to delete their home directory.