10 DISM (Deployment Image Servicing and Management) Interview Questions and Answers

Deployment Image Servicing and Management (DISM) is a powerful command-line tool used for servicing and preparing Windows images, including those used for Windows PE, Windows Recovery Environment (Windows RE), and Windows Setup. DISM can be used to mount and service a Windows image from a .wim file, .ffu file, or a virtual hard disk (.vhd or .vhdx). It is an essential tool for IT professionals and system administrators who need to manage and deploy Windows operating systems efficiently.

This article provides a curated selection of DISM-related interview questions designed to help you demonstrate your expertise in managing Windows images. By familiarizing yourself with these questions and their answers, you will be better prepared to showcase your technical proficiency and problem-solving abilities in your upcoming interview.

DISM (Deployment Image Servicing and Management) Interview Questions and Answers

1. How would you mount and unmount a Windows image? Provide the commands.

To mount a Windows image using DISM, use:

dism /Mount-WIM /WimFile:C:\path\to\your\image.wim /index:1 /MountDir:C:\mount\directory

In this command:

• /WimFile specifies the path to the WIM file.
• /index specifies the index of the image within the WIM file.
• /MountDir specifies the directory where the image will be mounted.

To unmount the Windows image, use:

dism /Unmount-WIM /MountDir:C:\mount\directory /commit

In this command:

• /MountDir specifies the directory where the image is mounted.
• /commit saves any changes made to the image. If you do not want to save changes, use /discard instead.

2. Write the command to add a driver to an offline image.

To add a driver to an offline image using DISM, use:

dism /image:C:\offline /add-driver /driver:C:\drivers\driver.inf

In this command:

• /image:C:\offline specifies the path to the offline image.
• /add-driver indicates that you want to add a driver.
• /driver:C:\drivers\driver.inf specifies the path to the driver .inf file.

3. How do you service an offline image to enable a specific Windows feature? Provide the command.

To enable a specific Windows feature in an offline image, use:

dism /image:C:\offline /enable-feature /featurename:NetFx3 /all /source:D:\sources\sxs /limitaccess

In this command:

• /image:C:\offline specifies the path to the offline image.
• /enable-feature indicates that you want to enable a feature.
• /featurename:NetFx3 specifies the name of the feature to enable (in this case, .NET Framework 3.5).
• /all enables all parent features of the specified feature.
• /source:D:\sources\sxs specifies the location of the feature files.
• /limitaccess prevents DISM from contacting Windows Update for additional source files.

4. Which command would you use to check the health of an image, and how would you repair it if needed?

To check the health of an image using DISM, use:

DISM /Online /Cleanup-Image /CheckHealth

If the image needs repair, use:

DISM /Online /Cleanup-Image /RestoreHealth

This command scans the image for corruption and performs repair operations automatically.

5. Describe the process and provide the command to apply updates to an offline image.

To apply updates to an offline image, follow these steps:

• Mount the offline image.
• Apply the updates.
• Commit the changes and unmount the image.

Use the following command:

dism /image:C:\mount\windows /add-package /packagepath:C:\updates\update.msu

In this command:

• /image:C:\mount\windows specifies the path to the mounted offline image.
• /add-package indicates that you are adding a package to the image.
• /packagepath:C:\updates\update.msu specifies the path to the update package you want to apply.

6. How do you clean up an image to reduce its size? Provide the command.

To clean up an image and reduce its size, use:

dism /Online /Cleanup-Image /StartComponentCleanup /ResetBase

This command performs several actions:

• The /Online switch targets the running operating system.
• The /Cleanup-Image switch specifies that you want to clean up the image.
• The /StartComponentCleanup switch removes previous versions of components that are no longer needed.
• The /ResetBase switch resets the base of the image, which further reduces the size by removing superseded versions of components.

7. Write a PowerShell script that mounts an image, adds a driver, and then unmounts the image.

To mount an image, add a driver, and then unmount the image using DISM in PowerShell, use the following script:

# Define variables
$imagePath = "C:\path\to\your\image.wim"
$mountPath = "C:\path\to\mount\directory"
$driverPath = "C:\path\to\driver\directory"

# Mount the image
dism /Mount-Wim /WimFile:$imagePath /Index:1 /MountDir:$mountPath

# Add the driver
dism /Image:$mountPath /Add-Driver /Driver:$driverPath /Recurse

# Unmount the image and commit changes
dism /Unmount-Wim /MountDir:$mountPath /Commit

8. How do you apply an unattended answer file to an image? Provide the command.

To apply an unattended answer file to an image using DISM, use:

dism /image:C:\mount /apply-unattend:C:\path\to\unattend.xml

In this command:

• /image:C:\mount specifies the path to the mounted image.
• /apply-unattend:C:\path\to\unattend.xml specifies the path to the unattended answer file.

9. What techniques can be used to optimize the size of a Windows image? Provide relevant commands.

To optimize the size of a Windows image, several techniques can be employed:

• Removing Unnecessary Features and Packages: Use DISM /Remove-Package and DISM /Disable-Feature commands.
• Cleaning Up the Image: Use DISM /Cleanup-Image to remove superseded components.
• Compressing the Image: Use DISM /Export-Image to export and compress the image.
• Removing Temporary Files: Use DISM /Cleanup-Image /StartComponentCleanup to remove unnecessary data.

Relevant commands:

# Remove a specific package
DISM /Image:C:\mount /Remove-Package /PackageName:PackageName

# Disable a specific feature
DISM /Image:C:\mount /Disable-Feature /FeatureName:FeatureName

# Clean up the image
DISM /Image:C:\mount /Cleanup-Image /StartComponentCleanup

# Export and compress the image
DISM /Export-Image /SourceImageFile:C:\images\install.wim /SourceIndex:1 /DestinationImageFile:C:\images\install_compressed.wim /Compress:max

10. How would you customize Windows features in an image? Provide an example command.

To customize Windows features in an image, use the DISM tool with specific commands to enable or disable features. This is useful for creating a tailored Windows installation.

Example command to enable a feature:

dism /image:C:\mount\windows /enable-feature /featurename:NetFx3 /all

In this example, the command enables the .NET Framework 3.5 feature in the mounted Windows image located at C:\mount\windows.