Windows Defender Install Sufficient Privileges

JPearce Hi all,

So in my travels with Microsoft Support so far, we've tried the following:

-Ensuring that the prerequisite KBs (KB2999226, KB3080149, KB5006714) are installed prior to running the md4ws.msi file

-Ensuring that the .msi is called using the official MS Down-level device deployment script (https://raw.githubusercontent.com/microsoft/mdefordownlevelserver/main/Install.ps1)

-Installing using system context through PsExec, same result

-Applying a Sense Client standalone upgrade package before installing/after failed install to see if it works, same result

I've found that through painstaking trial and error, devices that have had the error can be onboarded, but there appears to be no rhyme or reason to when the device will let you do it - One had issues all afternoon that I replicated in a live session with the Microsoft engineer, trying all of the above and more - the next morning it worked on the first attempt. I'm finding this true for a few of them.

In addition, on the devices we've managed to onboard, I've found an issue where defining a proxy for DfE to use through local group policy or through the 'TelemetryProxyServer' registry value is not working, and the only way to get it to onboard is to temporarily define a system-wide WinHTTP proxy (which creates other issues and is not a great option). I'll post about that here too in case any of you are facing the same problems.

Thanks,

Josh