During the install, when prompted for a 'Network installation point:', enter the same directory as in step 3 above (e.g., C:\admininstall).
Select the License Manager location when prompted (or choose to define one later, if necessary).
Complete the install process.
At this point, there is a working package (with the service pack slipstreamed into it) that can be deployed using SMS, Group Policy, Active Directory, etc. The following steps explain how to silently install the package using a msiexec command.
Open a command prompt (Start > Run > cmd).
Enter the following at the command prompt:
msiexec /I <full path of setup.msi>\setup.msi INSTALLDIR=<desired location of install> ADDLOCAL=ALL ESRI_LICENSE_HOST=<License server hostname> SOFTWARE_CLASS=<product being installed> /qb
Note: There are more switches/options available with the msiexec command. Refer to the install.htm located on the ArcGIS Desktop disk (Installing ArcGIS Desktop > Installing ArcGIS Desktop Silently). Also, refer to the Deploying Managed ArcGIS 9.2 Setups link in the Related Information below.