Adding .Net 3.5 to install.wim with DISM

19 Feb

There seems to be some confusion on this from other posts, but this had worked solidly for me. In short, I tend to PXE deploy a vanilla Windows 10 image using WDS and then perform all my post-installation configuration using InTune and Group Policy.

I like to keep my deployed image completely clean but one thing I always end up needing is .net 3.5 for some legacy apps.

  1. Grab the latest Windows 10 build ISO from either MSDN or another location
  2. Mount the ISO
  3. Copy out the \sources\install.wim file and place it in a local directory, i.e. c:\temp
  4. Create a mount directory, i.e. c:\temp\mount
  5. Find the index number on the ISO with:  dism /Get-WimInfo /WimFile:c:\temp\install.wim (I use the Pro version)
  6. Mount the wim with:  dism /mount-image /imagefile:c:\temp\install.wim /index:8 /MountDir:c:\temp\mount
  7. Inject /Net 3.5 with: DISM /Image:c:\temp\mount /Enable-Feature /FeatureName:NetFx3 /All /LimitAccess /Source:D:\sxs
  8. Unmount and commit the changes: dism /unmount-wim /mountdir:”c:\temp\mount” /commit

Now you can pop that wim into WDS and it will deploy with .Net 3.5 alresady installed.