Latest Blog Posts

We're members of the

We've ridden there:


Layne's certifications:


Windows Installation Process Facts

Windows installation is divided into several phases, with each phase being called a configuration pass. Understanding how and when configuration passes run is key to a successful Windows image deployment. The following table identifies the steps used during a normal Windows installation.

Configuration Pass Description
windowsPE The windowsPEconfiguration pass is the first step in the installation process. The following steps are performed:
  1. If Windows PE is used, the WinPE environment is initialized. Tasks performed include:
    • Adding drivers required by WinPE (such as non-native drivers or network drivers if booting to a network share).
    • Creating WinPE log files or the page file.
  2. The Windows Setup program starts and performs the following:
    • The operating system edition to install is identified.
    • The product key is entered.
    • The hard disk is partitioned and formatted.
    • The Windows image is copied to the hard disk.
offlineServicing After the image file is copied to the computer, the offlineServicing configuration pass runs. During this pass, updates, drivers, and language packs are added to the Windows image. This pass runs after the image is copied to the computer and before the computer reboots.
specialize After the computer reboots, the specializepass runs and customizes the computer based on the specific computer hardware. During this stage, the following tasks are performed:
  • Configure the computer name.
  • Assign the computer a unique security identifier (SID).
  • Configure network and domain settings.
oobeSystem The oobeSystem configuration pass runs following the specializepass and configures Windows settings prior to the Windows Welcome screen showing. During this stage, the following tasks are performed:
  • Create and configure initial user accounts.
  • Configure Windows Shell options.
  • Identify language and locale settings (such as the time zone).
After the oobeSystem pass runs, the installation process is complete.

In addition to the basic configuration passes described in the previous table, the following additional configuration passes might also run when preparing and deploying a system image. Note: These passes do not normally run unless you specifically configure the setup program to run them.

Configuration Pass Description
generalize The generalize pass prepares a system image for deployment to multiple computers by removing computer-specific information from the existing Windows installation. The generalizepass:
  • Runs after the offlineServicing pass and before the specialize pass.
  • Removes the computer SID and other hardware-specific information from the image.
auditSystem The auditSystem pass adds system configuration information to an image that has been installed on a computer. The auditSystempass:
  • Runs immediately after the specialize pass.
  • Runs before user logon.
  • Starts the computer in a special auditing mode.
    • During Audit mode, you can add drivers, install applications, and test the installation.
    • Audit mode does not display the Windows Welcome screen. When you start the computer in Audit mode, oobeSystem tasks are not performed.
    • Audit mode is used to customize an image before it is captured by loading additional drivers or installing applications.
    • Audit mode is also used after an image has been installed on the target computer to customize the specific computer or add applications used by the computer's user.
auditUser The auditUser pass runs when the computer starts in auditing mode after the user logs on. This pass runs after the auditSystempass.

Note: After the auditUser pass runs, the computer will continue to restart in Audit mode and will not enter oobeSystem mode until Audit mode is disabled.