SOLVED: Windows Deployment Services WDS hangs on “Windows is loading files” Status 0xc00000001 “Required Device Isn’t Connected”

If you are seeing your Windows Deployment Services WDS operating system installs stall on the WINDOWS IS LOADING FILES screen and then errors out with:

Windows Failed To Start
…
Status 0xc0000001
Required Device Isn’t Connected or Can’t Be Accessed

then have we got a fix for you!

To get to the point, it appears that in March 2019 Windows Update Patch KB4489882 and/or KB4489881 tighted up security on the TFTP (Trivial FTP) that WDS requires to transfer files to PC’s.  In the unlikely event you want more details see CVE-2019-0603.

The fix is a simple change in your WDS configuration:

1. Launch the Windows Deployment Services console
2. Expand SERVER
3. Right click on your server and select PROPERTIES
4. Select the TFTP tab
5. uncheck ENABLE VARIABLE WINDOW EXTENSION and click OK
6. Launch the SERVICES console
7. Restart your WINDOWS DEPLOYMENT SERVICES SERVER service
8. Try your deployment again

If you still have problems we found others had several different fixes that may help you:

1. Start (or restart) the WINDOWS LICENSE MANAGER SERVICE
2. Reduce the network speed on your NIC or on the switch port it is connected to to 100MB Full Duplex
3. Update the drivers available in WDS for the NIC you are using on the client PC
4. Uninstall KB4489982 and/or KB4489881 (not likely possible on Server 2016 / 2019)
5. Reboot your WDS server restart everything

In my case, we had just upgraded all of my customers network switches and found a few days later that our WDS had the WINDOWS IS LOADING FILES / REQUIRED DEVICE ISN’T CONNECTED failure so I was quiet sure it was related to the switches… I was wrong.  The problem was the patch.