Lab 13: Shrink your image size
Optimize your Windows image to save space on the PC, to speed up transfers to new devices, and to make it easier to store.
To do this, we'll use DISM tools that check for duplicate files. We'll mark the files for removal. These files won't be removed until we export the image.
Mount the images
Step 1: Mount the Windows image
Use the steps from Lab 3: Add device drivers (.inf-style) to mount the Windows image. The short version:
Open the command line as an administrator (Start > type deployment > right-click Deployment and Imaging Tools Environment > Run as administrator.)
Make a backup of the file (
copy "C:\Images\Win10_x64\sources\install.wim" C:\Images\install-backup.wim)
Mount the image (
md C:\mount\windows, then
Dism /Mount-Image /ImageFile:"C:\Images\install.wim" /Index:1 /MountDir:"C:\mount\windows" /Optimize)
Step 2: Optimizing the image, part 1 (optional)
After adding a language or Windows update package, you can reduce the size of the image size by checking for duplicate files and marking the older versions as superseded.
Optimize the image:
Dism /Image:c:\mount\windows /Cleanup-Image /StartComponentCleanup /ResetBase
Later, you'll export the image to remove the superseded files.
Step 3: Unmount the Windows image
Unmount and save the image:
Dism /Unmount-Image /MountDir:C:\mount\windows /Commit
Step 4: Optimizing the image, part 2 (optional)
If you've optimized the image, you'll need to export the image in order to see a change in the file size. During the export process, DISM removes files that were superseded.
Export the Windows image into a new image file.
Dism /Export-Image /SourceImageFile:"C:\Images\Win10_x64\sources\install.wim" /SourceIndex:1 /DestinationImageFile:"C:\Images\Win10_x64\sources\install-optimized.wim"
- When you're managing multiple Windows images, you can save even more space by combining them together. Learn how: Append a Volume Image to an Existing Image Using DISM.