Windows Preinstallation Environment (WinPE) is a lightweight, bare-bones version of Windows used extensively by enterprise IT departments for deploying operating systems, capturing disk images, and performing offline recovery. Because WinPE is exceptionally small, it only includes a generic set of Microsoft storage and networking drivers. If you attempt to boot a modern enterprise workstation—such as a Dell Precision or an HP ZBook with a proprietary RAID controller or a specialized 10GbE network adapter—WinPE will fail to see the hard drive or connect to the network deployment share. To resolve this, administrators must permanently inject unsigned or proprietary Original Equipment Manufacturer (OEM) drivers directly into the WinPE boot image using the Deployment Image Servicing and Management (DISM) command-line tool.
Preparing the Offline Servicing Environment
You cannot modify a WinPE image while you are booted into it. The modification process, known as “offline servicing,” must be performed on an administrator workstation running the Windows Assessment and Deployment Kit (ADK).
First, you must create a structured directory environment to mount the image. Open an elevated Command Prompt and execute the following commands to create the necessary folders on your root drive:
mkdir C:\WinPE_Servicing\Mount
mkdir C:\WinPE_Servicing\DriversLocate your core WinPE image file, typically named boot.wim, and copy it into the C:\WinPE_Servicing\ directory. Finally, extract the specific .inf, .sys, and .cat files provided by your hardware manufacturer and place them directly into the \Drivers folder. Ensure the files are completely extracted; DISM cannot inject drivers from within an executable (.exe) installer.
Mounting the WIM Image with DISM
To inject the drivers, you must instruct DISM to mount the boot.wim file and expand its internal file structure into your empty \Mount directory.
dism /Mount-Image /ImageFile:C:\WinPE_Servicing\boot.wim /Index:1 /MountDir:C:\WinPE_Servicing\MountThe /Index:1 parameter is critical. A standard boot.wim file often contains two separate images. Index 1 is the core Windows PE environment, and Index 2 is usually the Windows Setup environment. You must mount Index 1 to inject drivers into the actual boot environment.
Injecting the Unsigned OEM Drivers
Once the image is mounted, use the /Add-Driver command to inject the hardware drivers. By utilizing the /Recurse flag, DISM will automatically scan the specified folder and inject every valid .inf file it discovers.
dism /Image:C:\WinPE_Servicing\Mount /Add-Driver /Driver:C:\WinPE_Servicing\Drivers /RecurseBy default, Windows strictly enforces driver signature verification. If an OEM provides a specialized storage controller driver that lacks a valid Microsoft WHQL (Windows Hardware Quality Labs) digital signature, DISM will reject the injection and throw an error. To bypass this security check and force the integration of unsigned drivers specifically into the WinPE environment, you must append the /ForceUnsigned parameter.
dism /Image:C:\WinPE_Servicing\Mount /Add-Driver /Driver:C:\WinPE_Servicing\Drivers /Recurse /ForceUnsignedDISM will parse the directory and output a confirmation log indicating exactly how many driver packages were successfully installed into the offline image store.
Committing Changes and Unmounting
The driver files have now been physically copied into the mounted file system, and the offline Windows Registry has been updated. However, the changes exist only in the temporary mount directory. You must instruct DISM to commit these changes back into the original boot.wim file.
dism /Unmount-Image /MountDir:C:\WinPE_Servicing\Mount /CommitIf you encounter an error or realize you injected the wrong drivers, you can discard the changes entirely by replacing /Commit with /Discard.
Once the unmount process completes, the boot.wim file in your working directory is fully updated. You can now replace the old boot.wim on your USB deployment media or Windows Deployment Services (WDS) server with this customized version. When the workstation boots, the WinPE kernel will instantly load the injected OEM drivers, granting full access to proprietary RAID arrays and advanced network interfaces.