In modern UNIX and Linux systems, user passwords are encrypted and stored in the /etc/shadow file. On BSD systems, the passwords are kept in the /etc/master.passwd file. The encrypted password field in the file contains more than just the encrypted password, it contains additional information.

You can change the Windows Domain User Account Password from the Command Line using the net command. This is applicable to Windows NT line of operating systems – NT 4, Windows 2000, Windows XP Pro, Windows Vista and so on.

If you have set a root password for MySQL previously, but have forgotten what it was, you can reset the password without much hassle.

Never leave your Firefox browser unattended with your password keyed in. Your password can be stolen even before you know it.