How can I disable the Windows Game DVR from the command line?

I need to disable the Windows Game DVR for a collection of Windows computers that will be running student exam / testing software, so that students can't use the Game DVR hotkeys to record the test questions and choices.

These computers are not Windows 10 Home edition so group policy can be used, but they are also not managed by Active Directory, SCCM, or Azure Endpoint Manager. Is there a way to do it from the command line?

One way to disable the Game DVR from the command line is by using REG.EXE at an elevated command prompt like this:

reg.exe add "HKLM\Software\Policies\Microsoft\Windows\GameDVR" /v "AllowGameDVR" /t REG_DWORD /d 0

If you want to overwrite any previous value, add /f at the end of this command to force the change without prompting.

Explanation:

Microsoft group policy documentation at https://docs.microsoft.com/en-us/windows/client-management/mdm/policy-csp-applicationmanagement#applicationmanagement-allowgamedvr

Says that this policy is found in C:\Windows\PolicyDefinitions\GameDVR.admx

On my Windows 10 21H2 the policy looks like this:

<policy name="AllowGameDVR" class="Machine"
displayName="$(string.GameDVRMode)"
explainText="$(string.GameDVRMode_Help)"
key="Software\Policies\Microsoft\Windows\GameDVR"
valueName="AllowGameDVR">
  <parentCategory ref="GAMEDVR" />
  <supportedOn ref="windows:SUPPORTED_Windows_10_0_NOSERVER" />
  <enabledValue>
    <decimal value="1" />
  </enabledValue>
  <disabledValue>
    <decimal value="0" />
  </disabledValue>
</policy>

It is policy class Machine so it is in the HKEY_LOCAL_MACHINE or HKLM registry hive.

The registry path is Software\Policies\Microsoft\Windows\GameDVR

To disable it, you create the key name AllowGameDVR with a decimal value (or DWORD) of 0