Windows Vista, Windows 7, Windows Server 2008 R2, Windows 8.1, and Windows 10 setup log file locations

This article describes where to locate these log files and which log files are most useful for troubleshooting each setup phase of Windows 7, of Windows Server 2008 R2, and of Windows Vista.

Original product version:   Windows 10 - all editions, Windows Server 2019, Windows Server 2016
Original KB number:   927521

Introduction

Windows setup log files are in different locations on the hard disk. These locations depend on the setup phase.

Support for Windows Vista without any service packs installed ended on April 13, 2010. To continue receiving security updates for Windows, make sure you're running Windows Vista with Service Pack 2 (SP2). For more information, see Windows XP support has ended.

Down-level phase

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

Log file Description
C:\WINDOWS\setupapi.log Contains information about device changes, driver changes, and major system changes, such as service pack installations and hotfix installations.

This log file is used only by Microsoft Windows XP and earlier versions.
C:$WINDOWS.~BT\Sources\Panther\setupact.log Contains information about setup actions during the installation.
C:$WINDOWS.~BT\Sources\Panther\setuperr.log Contains information about setup errors during the installation.
C:$WINDOWS.~BT\Sources\Panther\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
C:$WINDOWS.~BT\Sources\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel 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.

Log file Description
X:$WINDOWS.~BT\Sources\Panther\setupact.log Contains information about setup actions during the installation.
X:$WINDOWS.~BT\Sources\Panther\setuperr.log Contains information about setup errors during the installation.
X:$WINDOWS.~BT\Sources\Panther\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
X:$WINDOWS.~BT\Sources\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel phase.
or
C:$WINDOWS.~BT\Sources\Panther\setupact.log Contains information about setup actions during the installation.
C:$WINDOWS.~BT\Sources\Panther\setuperr.log Contains information about setup errors during the installation.
C:$WINDOWS.~BT\Sources\Panther\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
C:$WINDOWS.~BT\Sources\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel phase.

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 select 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 it's an upgrade installation, data and programs are also migrated. The following table lists important log files in this setup phase.

Log file Description
C:\WINDOWS\PANTHER\setupact.log Contains information about setup actions during the installation.
C:\WINDOWS\PANTHER\setuperr.log Contains information about setup errors during the installation.
C:\WINDOWS\PANTHER\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
C:\WINDOWS\INF\setupapi.dev.log Contains information about Plug and Play devices and driver installation.
C:\WINDOWS\INF\setupapi.app.log Contains information about application installation.
C:\WINDOWS\Panther\PostGatherPnPList.log Contains information about the capture of devices that are on the system after the online configuration phase.
C:\WINDOWS\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel 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 signs in. The following table lists important log files in this setup phase.

Log file Description
C:\WINDOWS\PANTHER\setupact.log Contains information about setup actions during the installation.
C:\WINDOWS\PANTHER\setuperr.log Contains information about setup errors during the installation.
C:\WINDOWS\PANTHER\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
C:\WINDOWS\INF\setupapi.dev.log Contains information about Plug and Play devices and driver installation.
C:\WINDOWS\INF\setupapi.app.log Contains information about application installation.
C:\WINDOWS\Panther\PostGatherPnPList.log Contains information about the capture of devices that are on the system after the online configuration phase.
C:\WINDOWS\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel phase.
C:\WINDOWS\Performance\Winsat\winsat.log Contains information about the Windows System Assessment Tool performance testing results.

Rollback phase

If a Windows upgrade installation fails, and you've 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.

Log file Description
C:$WINDOWS.~BT\Sources\Panther\setupact.log Contains information about setup actions during the installation.
C:$WINDOWS.~BT\Sources\Panther\miglog.xml Contains information about the user directory structure. This information includes security identifiers (SIDs).
C:$WINDOWS.~BT\Sources\Panther\setupapi\setupapi.dev.log Contains information about Plug and Play devices and driver installation.
C:$WINDOWS.~BT\Sources\Panther\setupapi\setupapi.app.log Contains information about application installation.
C:$WINDOWS.~BT\Sources\Panther\PreGatherPnPList.log Contains information about the initial capture of devices that are on the system during the downlevel phase.
C:$WINDOWS.~BT\Sources\Panther\PostGatherPnPList.log Contains information about the capture of devices that are on the system after the online configuration phase.