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:
/WimFilespecifies the path to the WIM file./indexspecifies the index of the image within the WIM file./MountDirspecifies 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:
/MountDirspecifies the directory where the image is mounted./commitsaves any changes made to the image. If you do not want to save changes, use/discardinstead.
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:\offlinespecifies the path to the offline image./add-driverindicates that you want to add a driver./driver:C:\drivers\driver.infspecifies 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:\offlinespecifies the path to the offline image./enable-featureindicates that you want to enable a feature./featurename:NetFx3specifies the name of the feature to enable (in this case, .NET Framework 3.5)./allenables all parent features of the specified feature./source:D:\sources\sxsspecifies the location of the feature files./limitaccessprevents 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\windowsspecifies the path to the mounted offline image./add-packageindicates that you are adding a package to the image./packagepath:C:\updates\update.msuspecifies 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
/Onlineswitch targets the running operating system. - The
/Cleanup-Imageswitch specifies that you want to clean up the image. - The
/StartComponentCleanupswitch removes previous versions of components that are no longer needed. - The
/ResetBaseswitch 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:\mountspecifies the path to the mounted image./apply-unattend:C:\path\to\unattend.xmlspecifies 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-PackageandDISM /Disable-Featurecommands. - Cleaning Up the Image: Use
DISM /Cleanup-Imageto remove superseded components. - Compressing the Image: Use
DISM /Export-Imageto export and compress the image. - Removing Temporary Files: Use
DISM /Cleanup-Image /StartComponentCleanupto 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.