Downlevel phase

The downlevel phase is the Windows setup phase that is run within the previous operating system. The following table lists important log files in this setup phase.

Windows Preinstallation Environment phase

The Windows Preinstallation Environment (Windows PE or WinPE) phase is the Windows setup phase that occurs after the restart at the end of the downlevel phase, or when you start the computer by using the Windows installation media. The following table lists important log files in this setup phase.

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Note You may also see a log file in the X:\WINDOWS directory. The Setupact.log file in this directory contains information about the progress of the initial options that are selected on the Windows installation screen. The Windows installation screen appears when you start the computer by using the Windows installation media. After you click Install now from the Windows installation screen, the Setup.exe file starts, and this log file is no longer used.

Online configuration phase

The online configuration phase (the first boot phase) starts when you receive the following message:

Please wait a moment while Windows prepares to start for the first time.

During this phase, basic hardware support is installed. If this is an upgrade installation, data and programs are also migrated. The following table lists important log files in this setup phase.

Windows Welcome phase

The Windows Welcome phase includes the following options and events:

It provides the options to create user accounts.
It provides the option to specify a name for the computer.
The Windows System Assessment Tool (Winsat.exe) finishes performance testing to determine the Windows Experience Index rating.

The Windows Welcome phase is the final setup phase before a user logs in. The following table lists important log files in this setup phase.

Rollback phase

If a Windows upgrade installation fails, and you have successfully rolled back the installation to the previous operating system desktop, there are several log files that you can use for troubleshooting. The following table lists important log files in this phase.