You can perform an installation, modify, repair, and uninstall using the ISA Server command-line tool as shown here:
PathToISASetup\Setup.exe [/[X|R]] /V" /q[b|n] FULLPATHANSWERFILE=\"PathToINIFile\INI_filename\""
The parameters are listed here:
PathToISASetup: The path to the ISA Server 2004 installation files. The path can be the root folder of the ISA Server CD or a shared folder on your network that contains the ISA Server files.
/R: Performs unattended reinstallation.
/X: Performs unattended uninstallation.
/V: Passes parameters to the Windows Installer engine, which enables the /q commands and the Answer File to be read. You will not require this option with a /X command.
INI_filename: The path to the answer file.
/Q [b|n]: Performs quiet unattended setup. If you specify b, a progress bar indicates the setup process. If you specify n, no dialog boxes are displayed.
PathToINIFile: The path to the folder containing the unattended installation information.
To modify the components installed in an unattended setup, type:
PathToISASetup\Setup.exe ADDLOCAL=NewFeature or REMOVE=FeatureToRemove
To repair an installation in an unattended setup, type:
Be aware of the following in order to avoid and overcome setup problems:
You must run Setup in the context of a server administrator.
You can't conduct an unattended installation on a computer with ISA Server 2000 already installed.
Notice that there is a backslash before the path to the answer file in the preceding command line. Be sure to provide the leading and trailing backslashes, and use quotation marks, or your installation probably will fail.
MSDE will not install correctly if you are connected to the ISA server using Terminal Services Application mode. You can use a Remote Desktop session and execute the command, or execute the command using Sysinternals's PSExec.exe tool, available free from http://www.sysinternals.com. See http://support.microsoft.com/kb/830629/ for more information.