In password-protected Windows XP Home or Professional edition system, each user logs on to his or her own user name and password to have full access to the Windows computer. However, Windows user or administrator can still log in to the Windows XP machine without knowing the original password, if they have lost or forgotten the user ID or password, by using various bypass or crack method such as using DreamPackPL to bypass the need to logon using valid account or password, brute force retrieve the Windows passwords for various user or administrator account with Ophcrack, and using third party services such as Login Recovery to retrieval and recovery of Windows user name and passwords. However, there is one simpler method to hack into a Windows XP system, if the computer owner installed Windows XP, and forgot or not set the Administrator account password.

By default installation, Windows XP has a built-in Administrator account, which is equivalent to root or superuser privilege account in Linux or Unix, and contains no password. In other word, hacker or any people can simply key in Administrator as user name at the Windows Logon Welcome Screen prompt with blank password (no password) and get full administrative access as superuser to the Windows PC. Worse, most computer owners don’t even know such an Administrator account is actually existed, don’t even mention they will create or set a password for Administrator user account.

Windows XP Welcome Screen

So this security vulnerability flaw provides an easy way to login into any Windows XP computer that the user forgets or simply does not set a password for the Administrator user ID. The problem is that in normal Windows XP Welcome Screen where you choose which user name you want to log onto, the Administrator user name is not displayed and is not shown. If you can’t choose or select the Administrator from the login screen, then how are you going to log-in with the Administrator account? The following video clip provides a simple hack and trick.

Video no longer available

Basically, at Windows XP Welcom Screen, simply press Ctrl + Alt + Del keys sequence together twice, and you will be shown a “Log On to Windows” menu which you can specify User Name and Password. In the User Name text box, key in Administrator and leave the Password field blank. Then press Enter or click on OK. If there is not password protects the Administrator account, or blank password is set, then you will be able to access the Windows with full administrative privileges as Administrator.

Update: Ways to recover from forgotten Windows password.