Slow PXE boot performance on a UEFI computer that's running Windows 8.1 or Windows Server 2012 R2

To resolve this problem, apply the following hotfix.

Hotfix information

A supported hotfix is available from Microsoft Support. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, go to the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Installation information

To apply this hotfix, follow these steps:

1. Export the Windows 8.1 or Windows Server 2012 R2 boot image from the Windows Deployment Services (WDS) server. To do this, follow these steps:
   1. Run the WDS Microsoft Management Console (MMC) snap-in or the Windows Deployment Services command-line tool (Wdsutil.exe).
   2. Locate the boot image that you plan to use.
   3. Right-click that image, and then export it to a known location. For example, you might create a folder on the root of drive C, such as C:\bin.
2. Mount the exported boot image by using the index number. For example, mount index 2 of the boot image. To do this, follow these steps:
   1. Open an administrative Command Prompt window. For example, right-click in the lower-left corner of your desktop, and then click Command prompt (admin).
   2. Type the following command, and then press Enter:
      
      
      cd \bin
   3. Type the following command, and then press Enter to obtain information about the Wim:
      
      
      dism.exe /get-wiminfo /wimfile:c:\bin\exportedwim.wim
      Note This is to determine whether you have one or two indexes in this .wim file.
      
   4. Create a new mount folder where the .wim file will be mounted for file injection. To do this, type the following command, and then press Enter:
      
      
      md c:\bin\mount
   5. Type the following command to mount the .wim file:
      
      
      dism /mount-wim /wimfile:c:\bin\exportedwim.wim /index:2 /mountdir:c:\bin\mount
      Note If there are two indexes, such as when you use the default boot.wim file to create boot.wim for WDS, use the second index.
3. Install the .msu package to the Windows 8.1 or Windows Server 2012 R2 boot.wim file to add this update to the boot image.
   
   Note Although the referenced article is for Windows 7, the commands to add this update to the boot image still apply. Specifically, follow these steps to add this update to the boot image:
   1. To add this update to the boot image, run the following command:
      
      
      dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:Path_to_package
      
      
   2. To commit the changes after the update package is successfully installed, run the following command:
      
      
      dism.exe /unmounts-wim /mountdir:c:\bin\mount /commit
4. Replace the boot image on the WDS server by using the updated boot image. To add the updated Boot.wim file back to the WDS server, follow these steps or use the Wdsutil.exe utility:
   1. Open the WDS MMC snap-in.
   2. Right-click Boot Images, click Add Boot Image, and then specify the path of the updated Boot.wim file.
   3. After the updated boot image is added back to the WDS server, right-click the boot image to make sure that it's enabled.

Prerequisites

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any previously released hotfix.