password

How do I get a password from Windows XP, Administrator? A password was not used in setup (Home edition), but I cannot login except as a user. In Control Panel/User accounts, Administrator is not displayed. How do I change the Administrator password, so I can logon as Administrator? I press CTRL-ALT-DEL twice to logon, but it wants a password even though there is none. Is there a standard password for Administrator? Please help.