Windows Components › Microsoft Defender Antivirus › Real-time Protection
Configure performance mode status
Supported on SUPPORTED_Windows_11_0_22H1 (defined in the Windows templates)
What it does
This policy controls Microsoft Defender Antivirus performance mode for Dev Drives. A Dev Drive is a disk drive optimized for higher performance in software development scenarios. When this policy is Enabled or not configured, Performance mode is turned on for Microsoft Defender Antivirus. In Performance mode, Microsoft Defender Antivirus security checks of content stored on Dev Drives are conducted asynchronously to enhance performance. Performance mode requires the following policies also be enabled: “Enable dev drive”, and “Dev drive filter attach policy”. If you either Enable or do not configure this policy setting, Performance mode is turned on. If you Disable this policy setting, Performance mode is turned off and Microsoft Defender Antivirus will protect a Dev Drive in the same way as other drives.
What it writes
- Hive
- HKEY_LOCAL_MACHINE
- Registry key
Software\Policies\Microsoft\Windows Defender\Real-Time Protection- Value name
DisableAsyncScanOnOpen- When enabled
- DWORD 0
- When disabled
- DWORD 1
Why it needs changes for Intune
- Policy references a Windows supportedOn definition.
- ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE
In Intune
No native CSP; import the ADMX (needs changes first).
From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.
Configure and deploy
Choose a state; the output below is generated from the template for exactly that.
Enabled · Computer · template defaults
Registry file (.reg)
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection]
"DisableAsyncScanOnOpen"=dword:00000001
PowerShell
$ErrorActionPreference = 'Stop'
function Set-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $PropertyType,
[Parameter(Mandatory = $true)][object] $Value
)
if (-not (Test-Path -LiteralPath $Path)) {
New-Item -Path $Path -Force | Out-Null
}
New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}
function Remove-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (Test-Path -LiteralPath $Path) {
Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
}
}
function Clear-RegistryKeyValues {
param(
[Parameter(Mandatory = $true)][string] $Path
)
if (-not (Test-Path -LiteralPath $Path)) {
return
}
foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Configure performance mode status
# Name: RealtimeProtection_PerformanceModeStatus
# Scope: Machine
# State: Enabled
# Source: WindowsDefender.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -PropertyType 'DWord' -Value 0
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -PropertyType 'DWord' -Value 1
- The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
- Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.
ADMX profile candidate (OMA-URI)
./Device/Vendor/MSFT/Policy/Config/ADMX_WindowsDefender/RealtimeProtection_PerformanceModeStatusADMX SyncML candidate
<SyncML xmlns="SYNCML:SYNCML1.2">
<SyncBody>
<Replace>
<CmdID>1</CmdID>
<Item>
<Meta>
<Format>chr</Format>
<Type>text/plain</Type>
</Meta>
<Target>
<LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_WindowsDefender/RealtimeProtection_PerformanceModeStatus</LocURI>
</Target>
<Data><enabled/></Data>
</Item>
</Replace>
<Final/>
</SyncBody>
</SyncML>Intune remediation scripts
Detection
$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()
function Test-RegistryValueExists {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (-not (Test-Path -LiteralPath $Path)) {
return $false
}
return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}
function Test-RegistryValueEquals {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $Kind,
[Parameter(Mandatory = $true)][object] $Expected
)
if (-not (Test-Path -LiteralPath $Path)) {
return $false
}
$valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
if ($null -eq $valueObject) {
return $false
}
$actual = $valueObject.$Name
switch ($Kind) {
'String' { return [string]$actual -ceq [string]$Expected }
'ExpandString' { return [string]$actual -ceq [string]$Expected }
'DWord' { return [uint32]$actual -eq [uint32]$Expected }
'QWord' { return [uint64]$actual -eq [uint64]$Expected }
'MultiString' {
$actualArray = @($actual)
$expectedArray = @($Expected)
if ($actualArray.Count -ne $expectedArray.Count) { return $false }
for ($index = 0; $index -lt $actualArray.Count; $index++) {
if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
}
return $true
}
'Binary' {
$actualArray = [byte[]]$actual
$expectedArray = [byte[]]$Expected
if ($actualArray.Length -ne $expectedArray.Length) { return $false }
for ($index = 0; $index -lt $actualArray.Length; $index++) {
if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
}
return $true
}
default { return [string]$actual -ceq [string]$Expected }
}
}
# Policy: Configure performance mode status
# Name: RealtimeProtection_PerformanceModeStatus
# Scope: Machine
# State: Enabled
# Source: WindowsDefender.admx
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -Kind 'DWord' -Expected 0
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection\DisableAsyncScanOnOpen') | Out-Null
}
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection\DisableAsyncScanOnOpen') | Out-Null
}
if ($reasons.Count -eq 0) {
Write-Output 'Compliant'
exit 0
}
$reasons | ForEach-Object { Write-Output $_ }
exit 1
Remediation
$ErrorActionPreference = 'Stop'
function Set-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $PropertyType,
[Parameter(Mandatory = $true)][object] $Value
)
if (-not (Test-Path -LiteralPath $Path)) {
New-Item -Path $Path -Force | Out-Null
}
New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}
function Remove-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (Test-Path -LiteralPath $Path) {
Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
}
}
function Clear-RegistryKeyValues {
param(
[Parameter(Mandatory = $true)][string] $Path
)
if (-not (Test-Path -LiteralPath $Path)) {
return
}
foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Configure performance mode status
# Name: RealtimeProtection_PerformanceModeStatus
# Scope: Machine
# State: Enabled
# Source: WindowsDefender.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -PropertyType 'DWord' -Value 0
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Real-Time Protection' -Name 'DisableAsyncScanOnOpen' -PropertyType 'DWord' -Value 1
History 5 retained releases
- 24H2 · 1.030 Sep 2024
- Added in this release.
1 later release left it unchanged.
Template
- Internal name
RealtimeProtection_PerformanceModeStatus- Namespace
Microsoft.Policies.WindowsDefender- Template file
WindowsDefender.admx- Release
- Windows 11 25H2 · 1.0 · file set
de4e49983ebd651f…
Definition, editor controls and support
Definition
<policy class="Machine" displayName="$(string.RealtimeProtection_PerformanceModeStatus)" explainText="$(string.RealtimeProtection_PerformanceModeStatus_Explain)" key="Software\Policies\Microsoft\Windows Defender\Real-Time Protection" name="RealtimeProtection_PerformanceModeStatus" valueName="DisableAsyncScanOnOpen" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.WindowsDefender:RealtimeProtection" />
<supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows_11_0_22H1" />
<enabledValue>
<decimal value="0" />
</enabledValue>
<disabledValue>
<decimal value="1" />
</disabledValue>
</policy>Editor controls
Supported platforms and category
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.WindowsDefender:category:AntiSpywareDefender
<category displayName="$(string.AntiSpywareDefender)" name="AntiSpywareDefender" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
</category>
Microsoft.Policies.WindowsDefender:category:RealtimeProtection
<category displayName="$(string.RealtimeProtection)" name="RealtimeProtection" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.WindowsDefender:AntiSpywareDefender" />
</category>
Microsoft.Policies.WindowsDefender:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows_11_0_22H1
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows_11_0_22H1" />
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:WindowsComponents">Windows Components</string><string id="Microsoft.Policies.Windows:WindowsComponents_Help">Contains settings for operating system components.</string></strings>
Microsoft.Policies.WindowsDefender:category:AntiSpywareDefender
<category displayName="$(string.AntiSpywareDefender)" name="AntiSpywareDefender" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
</category>
<strings><string id="Microsoft.Policies.WindowsDefender:AntiSpywareDefender">Microsoft Defender Antivirus</string></strings>
Microsoft.Policies.WindowsDefender:category:RealtimeProtection
<category displayName="$(string.RealtimeProtection)" name="RealtimeProtection" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.WindowsDefender:AntiSpywareDefender" />
</category>
<strings><string id="Microsoft.Policies.WindowsDefender:RealtimeProtection">Real-time Protection</string></strings>