Windows Updates

A required device isn’t connected or can’t be accessed – July 2019 Update

Back in March 2019 I had an issue with a required device isn’t connected or can’t be accessed while using MDT/WDS.

This was due to a bug in the March cumulative update.

The solution was to disable TFTP Variable Window Extension inside the WDS properties.

This issue was fixed with the June cumulative update KB4503285 (Server 2012), KB4503276 (Server 2012 R2) KB4503267 (Server 2016) and KB4503327 (Server 2019)

I have been reading of many cases where the June CU KB4503276 for Server 2012 R2, which was meant to fix the PXE booting issue is causing a PXE boot issue in WDS/MDT/SCCM.


  1. Uninstall KB4503276 if you are running Server 2012 R2.

Note: If you are using SCCM, you can turn on the native SCCM PXE server:

  1. Go to Administration > Distribution Points
  2. Open the properties of your DP > PXE Tab
  3. Tick “Enable a PXE responder without Windows Deployment Services”.
  4. This will take a few minutes and no reboot is required.

I hope this info helps everyone.

Please comment if you have experienced this issue?

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