reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\Client" /v AuthenticationLevelOverrideEnabled /t REG_DWORD /d 1 /f
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\Client" /v AuthenticationLevelOverride /t REG_DWORD /d 0 /f

gpupdate /force

Falls Schlüssel existiert:
reg add "HKLM\Software\Policies\Microsoft\Windows NT\Terminal Services\Client" /v RedirectionWarningDialogVersion /t REG_DWORD /d 1 /f

falls nicht:
reg add "HKLM\Software\Policies\Microsoft\Windows NT\Terminal Services\Client" /f
reg add "HKLM\Software\Policies\Microsoft\Windows NT\Terminal Services\Client" /v RedirectionWarningDialogVersion /t REG_DWORD /d 1 /f

Prüfung:
reg query "HKLM\Software\Policies\Microsoft\Windows NT\Terminal Services\Client"

Ausgabe sollte sein: RedirectionWarningDialogVersion    REG_DWORD    0x1

Powersehll:
New-Item -Path "HKLM:\Software\Policies\Microsoft\Windows NT\Terminal Services\Client" -Force
New-ItemProperty -Path "HKLM:\Software\Policies\Microsoft\Windows NT\Terminal Services\Client" -Name "RedirectionWarningDialogVersion" -PropertyType DWord -Value 1 -Force