If you do not know the local user account and password, you cannot log on to the computer. To resolve this issue, use one of the following methods, as appropriate for your operating system.
For Microsoft Windows NT 4.0Use a recent copy of the Microsoft Windows NT Emergency Repair Disk (ERD) to restore the registry files on the system. This resolution lets you restore the computer's user database (or SAM) to a version for which you have a correct user name and password.
Be aware that when you replace the SAM from the ERD, this replaces the user accounts and passwords with those that existed on the date that the ERD was created. Therefore, when you use an account that was created by using this method, you have to know that account's password on the date that the ERD was created.
Also, depending on the options that were used when the ERD was created (such as whether the /S switch was used or not), the ERD may not include all existing user accounts.
By using the ERD, you are also required to start your computer from either the Windows NT 4.0 CD-ROM or from a boot disk, and to select the Repair option. During the repair process, select only the Registry option in the first window. Later in the repair process, a second window will offer options for which registry hives to repair. Select the SAM option.
For Windows XP or for Windows VistaUse a System Restore Point to restore the computer to the time at which the computer was added to the domain. Then, log on to the domain. Make sure that you know the user name and the password for an account in the local Administrators group. For more information, see the following Microsoft Knowledge Base article:
For more information about ERDs and how to perform an emergency repair in Windows NT, click the following article numbers to view the articles in the Microsoft Knowledge Base:
For more information about how to perform a Windows NT parallel installation, click the following article number to view the article in the Microsoft Knowledge Base: