Custom Classes: Deny read access

ComputerNative Intune settingCustomClasses_DenyRead_Access_2

Supported on At least Windows Vista

23H2 · 1.0

What it does

This policy setting denies read access to custom removable storage classes. If you enable this policy setting, read access is denied to these removable storage classes. If you disable or do not configure this policy setting, read access is allowed to these removable storage classes.

What it writes

Hive: HKEY_LOCAL_MACHINE
Registry key: Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read
Value name: Deny_Read
When enabled: DWORD 1
When disabled: DWORD 0

Why it needs changes for Intune

Policy references a Windows supportedOn definition.
ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE

In Intune

Native Intune setting: Yes — Policy CSP

./Device/Vendor/MSFT/Policy/Config/ADMX_RemovableStorage/CustomClasses_DenyRead_Access_2ADMX_RemovableStorage on Microsoft LearnADMX-backed: Windows ships this template, so it is set with the template's own values, without an import.Windows builds listed: 10.0.22000, 10.0.19043.1202, 10.0.19042.1202, 10.0.19041.1202.

From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.

Options

Option	Type	Registry value	Allowed values
GUID for custom removable storage class	List of values	`Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read\ListDeny_Read`	Any

Configure and deploy

Choose a state and the option values; 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\RemovableStorageDevices\Custom\Deny_Read]
"Deny_Read"=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: Custom Classes: Deny read access
# Name: CustomClasses_DenyRead_Access_2
# Scope: Machine
# State: Enabled
# Source: RemovableStorage.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read' -Name 'Deny_Read' -PropertyType 'DWord' -Value 1

These deployment candidates come from the ADMX template; they are separate from the native CSP mapping above.

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.
The generated payload is incomplete because one or more ADMX element values were not supplied: CustomClasses_List

ADMX profile candidate (OMA-URI)

./Device/Vendor/MSFT/Policy/Config/ADMX_RemovableStorage/CustomClasses_DenyRead_Access_2

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: Custom Classes: Deny read access
# Name: CustomClasses_DenyRead_Access_2
# Scope: Machine
# State: Enabled
# Source: RemovableStorage.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read' -Name 'Deny_Read' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read\Deny_Read') | 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: Custom Classes: Deny read access
# Name: CustomClasses_DenyRead_Access_2
# Scope: Machine
# State: Enabled
# Source: RemovableStorage.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read' -Name 'Deny_Read' -PropertyType 'DWord' -Value 1

History 3 retained releases

22H2 · 1.015 Jul 2024
- Already present in the first release ChangeIntel keeps.

2 later releases left it unchanged.

Template

Internal name: CustomClasses_DenyRead_Access_2
Namespace: Microsoft.Policies.RemovableStorageAccess
Template file: RemovableStorage.admx
Release: Windows 11 23H2 · 1.0 · file set d784d0ea5f14a680…

Definition, editor controls and support

Definition

<policy class="Machine" displayName="$(string.CustomClasses_DenyRead_Access)" explainText="$(string.CustomClasses_DenyRead_Access_help)" key="Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read" name="CustomClasses_DenyRead_Access_2" presentation="$(presentation.CustomClasses_DenyRead_Access_2)" valueName="Deny_Read" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.RemovableStorageAccess:DeviceAccess" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_WindowsVista" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
      <elements>
        <list additive="true" id="CustomClasses_List" key="Software\Policies\Microsoft\Windows\RemovableStorageDevices\Custom\Deny_Read\List" />
      </elements>
    </policy>

Editor controls

<presentation id="CustomClasses_DenyRead_Access_2" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <text>Enter GUID in format {xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxx},</text>
        <text>include brackets. Each custom GUID must be a separate entry</text>
        <listBox refId="CustomClasses_List">GUID for custom removable storage class:</listBox>
      </presentation>

Supported platforms and category

Microsoft.Policies.Products:product:MicrosoftWindows
sha256:4b3cb6917b5e5b7cd142c0157f10882786b3e9ee67c29fd7b8f4c6cb2eec5fe7
Microsoft.Policies.RemovableStorageAccess:category:DeviceAccess
<category displayName="$(string.DeviceAccess)" name="DeviceAccess" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:System" />
    </category>
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Windows:definition:SUPPORTED_WindowsVista
<definition displayName="$(string.SUPPORTED_WindowsVista)" name="SUPPORTED_WindowsVista" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <or>
          <range minVersionIndex="4" ref="Microsoft.Policies.Products:MicrosoftWindows" />
        </or>
      </definition>
Microsoft.Policies.Products:product:MicrosoftWindows
<product displayName="$(string.MicrosoftWindows)" name="MicrosoftWindows" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <majorVersion displayName="$(string.MicrosoftWindows2000)" name="MicrosoftWindows2000" versionIndex="1">
          <minorVersion displayName="$(string.MicrosoftWindows2000_RTM)" name="MicrosoftWindows2000_RTM" versionIndex="0" />
          <minorVersion displayName="$(string.MicrosoftWindows2000_SP1)" name="MicrosoftWindows2000_SP1" versionIndex="1" />
          <minorVersion displayName="$(string.MicrosoftWindows2000_SP2)" name="MicrosoftWindows2000_SP2" versionIndex="2" />
          <minorVersion displayName="$(string.MicrosoftWindows2000_SP3)" name="MicrosoftWindows2000_SP3" versionIndex="3" />
          <minorVersion displayName="$(string.MicrosoftWindows2000_SP4)" name="MicrosoftWindows2000_SP4" versionIndex="4" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsXP)" name="MicrosoftWindowsXP" versionIndex="2">
          <minorVersion displayName="$(string.MicrosoftWindowsXP_RTM)" name="MicrosoftWindowsXP_RTM" versionIndex="0" />
          <minorVersion displayName="$(string.MicrosoftWindowsXP_SP1)" name="MicrosoftWindowsXP_SP1" versionIndex="1" />
          <minorVersion displayName="$(string.MicrosoftWindowsXP_SP2)" name="MicrosoftWindowsXP_SP2" versionIndex="2" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsServer2003)" name="MicrosoftWindowsServer2003" versionIndex="3">
          <minorVersion displayName="$(string.MicrosoftWindowsServer2003_RTM)" name="MicrosoftWindowsServer2003_RTM" versionIndex="0" />
          <minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP1)" name="MicrosoftWindowsServer2003_SP1" versionIndex="1" />
          <minorVersion displayName="$(string.MicrosoftWindowsServer2003_R2)" name="MicrosoftWindowsServer2003_R2" versionIndex="2" />
          <minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP2)" name="MicrosoftWindowsServer2003_SP2" versionIndex="3" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsVista)" name="MicrosoftWindowsVista" versionIndex="4">
          <minorVersion displayName="$(string.MicrosoftWindowsVista_RTM)" name="MicrosoftWindowsVista_RTM" versionIndex="0" />
          <minorVersion displayName="$(string.MicrosoftWindowsVista_SP1)" name="MicrosoftWindowsVista_SP1" versionIndex="1" />
        </majorVersion>
        <majorVersion displayName="$(string.WindowsServer2008)" name="WindowsServer2008" versionIndex="5">
          <minorVersion displayName="$(string.WindowsServer2008_RTM)" name="WindowsServer2008_RTM" versionIndex="0" />
          <minorVersion displayName="$(string.WindowsServer2008_R2)" name="WindowsServer2008_R2" versionIndex="1" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows7)" name="MicrosoftWindows7" versionIndex="6">
          <minorVersion displayName="$(string.MicrosoftWindows7_RTM)" name="MicrosoftWindows7_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsServer8)" name="MicrosoftWindowsServer8" versionIndex="7">
           <minorVersion displayName="$(string.MicrosoftWindowsServer8_RTM)" name="MicrosoftWindowsServer8_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows8)" name="MicrosoftWindows8" versionIndex="8">
          <minorVersion displayName="$(string.MicrosoftWindows8_RTM)" name="MicrosoftWindows8_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows_RT)" name="MicrosoftWindows_RT" versionIndex="9">
          <minorVersion displayName="$(string.MicrosoftWindows_RT_RTM)" name="MicrosoftWindows_RT_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsServer_6_3)" name="MicrosoftWindowsServer_6_3" versionIndex="10">
           <minorVersion displayName="$(string.MicrosoftWindowsServer_6_3_RTM)" name="MicrosoftWindowsServer_6_3_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows_6_3)" name="MicrosoftWindows_6_3" versionIndex="11">
          <minorVersion displayName="$(string.MicrosoftWindows_6_3_RTM)" name="MicrosoftWindows_6_3_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows_6_3_RT)" name="MicrosoftWindows_6_3_RT" versionIndex="12">
            <minorVersion displayName="$(string.MicrosoftWindows_6_3_RT_RTM)" name="MicrosoftWindows_6_3_RT_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindowsServer_10_0)" name="MicrosoftWindowsServer_10_0" versionIndex="13">
            <minorVersion displayName="$(string.MicrosoftWindowsServer_10_0_RTM)" name="MicrosoftWindowsServer_10_0_RTM" versionIndex="0" />
          </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows_10_0)" name="MicrosoftWindows_10_0" versionIndex="14">
            <minorVersion displayName="$(string.MicrosoftWindows_10_0_RTM)" name="MicrosoftWindows_10_0_RTM" versionIndex="0" />
        </majorVersion>
        <majorVersion displayName="$(string.MicrosoftWindows_10_0_RT)" name="MicrosoftWindows_10_0_RT" versionIndex="15">
            <minorVersion displayName="$(string.MicrosoftWindows_10_0_RT_RTM)" name="MicrosoftWindows_10_0_RT_RTM" versionIndex="0" />
        </majorVersion>
      </product>
<strings><string id="Microsoft.Policies.Products:MicrosoftWindows">Windows operating system</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000">Windows 2000 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_RTM">Windows 2000</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP1">Windows 2000 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP2">Windows 2000 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP3">Windows 2000 Service Pack 3</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP4">Windows 2000 Service Pack 4</string><string id="Microsoft.Policies.Products:MicrosoftWindows7">Windows 7 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows7_RTM">Windows 7</string><string id="Microsoft.Policies.Products:MicrosoftWindows8">Windows 8 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows8_RTM">Windows 8</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003">Windows Server 2003 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_R2">Windows Server 2003 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_RTM">Windows Server 2003</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP1">Windows Server 2003 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP2">Windows Server 2003 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8">Windows Server 2012 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8_RTM">Windows Server 2012</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0">Windows Server 2016 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0_RTM">Windows Server 2016</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3">Windows Server 2012 R2 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3_RTM">Windows Server 2012 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista">Windows Vista operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_RTM">Windows Vista</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_SP1">Windows Vista Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP">Windows XP operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_RTM">Windows XP</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP1">Windows XP Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP2">Windows XP Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0">Windows 10 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT">Windows 10 RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RTM">Windows 10</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT_RTM">Windows 10 RT</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3">Windows 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT">Windows RT 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RTM">Windows 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT_RTM">Windows RT 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT">Windows RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT_RTM">Windows RT</string><string id="Microsoft.Policies.Products:WindowsServer2008">Windows Server 2008 operating systems</string><string id="Microsoft.Policies.Products:WindowsServer2008_R2">Windows Server 2008 R2</string><string id="Microsoft.Policies.Products:WindowsServer2008_RTM">Windows Server 2008</string></strings>
Microsoft.Policies.RemovableStorageAccess:category:DeviceAccess
<category displayName="$(string.DeviceAccess)" name="DeviceAccess" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:System" />
    </category>
<strings><string id="Microsoft.Policies.RemovableStorageAccess:DeviceAccess">Removable Storage Access</string></strings>
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:System">System</string><string id="Microsoft.Policies.Windows:System_Help">Allows configuration of various system component settings.</string></strings>
Microsoft.Policies.Windows:definition:SUPPORTED_WindowsVista
<definition displayName="$(string.SUPPORTED_WindowsVista)" name="SUPPORTED_WindowsVista" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <or>
          <range minVersionIndex="4" ref="Microsoft.Policies.Products:MicrosoftWindows" />
        </or>
      </definition>
<strings><string id="Microsoft.Policies.Windows:SUPPORTED_WindowsVista">At least Windows Vista</string></strings>