MS99-036: Unattended Installation File Is Not Deleted After Setup Finishes

When an unattended Windows NT 4.0 installation process finishes, a copy of the Unattend.txt file that contains installation parameters may remain on the hard disk. Depending on the method used to perform the installation, the file may contain sensitive information, potentially including the local Administrator user name and password.

To resolve this issue, ensure that the Unattend.txt file is reviewed and any sensitive information (including account information and passwords) is erased from the file, or delete the file altogether, after you perform an unattended installation of Windows NT 4.0.

To delete the file the first time a user logs on to the computer, use the Runonce feature in Windows NT 4.0 to run a batch file containing a command to delete the .inf file (depending on your type of Setup) containing the Setup information. For additional information about using the Runonce feature, please click the article number below to view the article in the Microsoft Knowledge Base:

When you perform an unattended installation of Windows NT 4.0, the installation parameters are included in the Unattend.txt file. Depending on the specific installation, the parameter file may contain sensitive information such as account identifiers and passwords. A vulnerability exists because the installation process copies the parameter file to a file in the %SystemRoot%\System32 folder (the $winnt$.inf file for a typical unattended installation, or the $nt4pre$.inf file if you use the System Preparation [Sysprep] tool), but does not delete the file when the installation is finished. By default, this file can be read by any user who is logged on locally.

For additional information about unattended installation, please click the article numbers below to view the articles in the Microsoft Knowledge Base: More information about the Sysprep tool is available at the following Microsoft Web site:

Microsoft Windows 2000

This does not affect installations of Windows 2000. During an unattended installation of Windows 2000, the Setup process deletes all sensitive information from the parameter file (upon successful completion). This occurs regardless of whether a normal unattended installation is performed or if Sysprep is used.