ADMX/ADML templates

Administrative Template XML (ADMX) and Administrative Template Language (ADML) files are administrative templates used by Group Policy to define and configure registry-based policy settings in Windows. ADMX files contain the policy definitions and structure, while ADML files provide the language-specific display strings, allowing IT administrators to manage policies across multilingual environments from a single set of templates.

Introduced with Windows Vista and Windows Server 2008, these templates replaced the older ADM format and remain the standard for Group Policy management in modern Windows environments, including Windows 11 and Windows Server 2025.

What are ADMX files?

ADMX files are policy definition files that tell the Group Policy Management Console (GPMC) which settings are available to configure and how they map to the Windows registry. Each ADMX file is a structured XML document that defines:

• The policy name and category placement in the GPO editor.
• The registry key, value name, and data type the policy modifies.
• The supported Windows versions for each policy.
• Default values, valid ranges, and dependencies between settings.

Unlike the legacy ADM format, ADMX files are language-neutral. The actual text shown in the Group Policy editor, such as policy names, descriptions, and option labels, are stored separately in ADML files.

Here's a sample ADMX file:

What are ADML files?

ADML files contain the localized display strings referenced by ADMX files. Each ADML file corresponds to a specific language and is stored in a language-specific subfolder. For example, English (United States) ADML files live in en-US, while German ADML files live in de-DE. When an administrator opens the GPMC, Windows automatically loads the ADML file matching the editor's display language.

This separation provides three major benefits:

• Single source of truth: One ADMX file serves administrators in every language.
• Easier translation: Vendors can ship multilingual templates by adding ADML files.
• Smaller storage footprint: Only required languages need to be deployed.

ADMX vs. ADML

Every .admx file requires a matching .adml language file in the appropriate language subfolder. The ADMX file is structural and declares the policy's category, the registry key and value it modifies, the supported Windows versions, and the enabled or disabled values. The ADML file is the localized text layer. When an admin opens the Group Policy Management Editor in English, Windows loads the matching en-US ADML; in German, it loads de-DE. The same ADMX file serves every language, which is the entire reason ADMX exists.

If the ADML file is missing, the policy still appears in the editor but with no readable name or description, and you'll often see errors referencing missing string resources. This is why it is essential to always copy both files together.

Key differences between ADM vs. ADMX

The legacy ADM format was replaced by ADMX starting with Windows Vista and Windows Server 2008. The table below summarizes the key differences between the two formats.

Where are ADMX Templates stored?

ADMX and ADML files have two possible storage locations, depending on whether you're managing policies locally or across a domain.

Local PolicyDefinitions folder

On every Windows computer, templates are stored at:

C:\Windows\PolicyDefinitions

While language-specific ADML files live in subfolders , for example:

C:\Windows\PolicyDefinitions\en-US

C:\Windows\PolicyDefinitions\de-DE

C:\Windows\PolicyDefinitions\fr-FR

This location is used when editing local Group Policy with gpedit.msc or when no Central Store exists in the domain.

Group Policy Central Store

In an Active Directory environment, templates should be stored centrally at:

For example:

When the GPMC detects this path on a domain controller (DC), it automatically loads templates from the Central Store instead of the local machine.

How to add ADMX Templates to the Central Store

The Central Store is a single, authoritative location hosted within Active Directory Domain Services (AD DS) that holds ADMX and ADML files for all GPOs in the domain. Without a Central Store, each administrator's workstation must have a current copy of the templates locally, which leads to inconsistency when technicians see different available policies based on their Windows version.

1. Download the ADMX package from the vendor and extract it to a temporary location.
2. Copy the .admx files into the root of the Central Store:
Click to copy script
\\<your-domain>\SYSVOL\<your-domain>\Policies\PolicyDefinitions\
3. Copy the matching .adml files into the appropriate language subfolder:
Click to copy script
\\<your-domain>\SYSVOL\<your-domain>\Policies\PolicyDefinitions\en-US\
4. Wait for SYSVOL/DFS-R replication to complete across all DCs.
5. Open GPMC, edit a GPO, and verify the new template categories appear under Computer Configuration > Administrative Templates or User Configuration > Administrative Templates.

How to install ADMX Templates on a local machine

For standalone Windows machines, workgroup environments, or any situation without Active Directory, install templates locally instead of using the Central Store. This is the right approach when you only need to edit local GPO on one or a handful of machines through the Local Group Policy Editor.

1. Extract the downloaded ADMX template package to a temporary folder.
2. Copy all .admx files into the local PolicyDefinitions folder:
   Click to copy script

   C:\Windows\PolicyDefinitions
3. Copy the matching .adml files into the appropriate language subfolder:
   Click to copy script

   C:\Windows\PolicyDefinitions\en-US
4. If prompted to replace existing files, choose Replace.
5. Open the Local Group Policy Editor by running gpedit.msc from the Start menu or Run dialog.
6. Navigate to Computer Configuration > Administrative Templates or User Configuration > Administrative Templates and verify the new policy categories appear.

Importing custom ADMX Templates into Microsoft Intune

For organizations using cloud-based device management, ADMX policies can be delivered to Windows clients without any on-premises Group Policy infrastructure. Intune offers two distinct paths: the built-in Settings Catalog for first-party policies, and Custom ADMX Import for third-party or non-built-in templates. Under the hood, the Policy Configuration Service Provider (Policy CSP) is the Windows component that translates ADMX-backed settings for MDM delivery into registry-based policy settings on the client.

Using the Settings Catalog for ADMX policies

The Intune Settings Catalog already ingests hundreds of ADMX-backed settings from Microsoft natively and you don't need to import anything manually for most Windows and Office policies. The Settings Catalog is the configuration interface for cloud-based device management, exposing policies in a searchable list.

1. Sign in to the Microsoft Intune admin center.
2. Go to Devices > Configuration > Create > New policy
3. Select Platform: Windows 10 and later and Profile type: Settings catalog
4. Click Add settings, then search for the policy by name.
5. Configure the policy and assign it to your target device groups.

Importing third-party ADMX Templates

Most major software vendors publish ADMX/ADML packages so administrators can manage their applications through Group Policy or Intune. Common third-party ADMX templates IT administrators deploy include:

To import third-party ADMX Templates via Intune:

1. Download the ADMX/ADML files for the product and save to an accessible folder, for example, C:\ADMXTemplates.
2. In the Intune admin center, go to Devices > Manage devices > Configuration > Import ADMX tab > Import
3. Upload the .admx file, then upload the matching .adml file for your default language.
4. Specify the ADML language and select Next.
5. Review and select Create to finish the import.
6. After upload status shows complete, create a configuration profile via Templates > Imported Administrative Templates (Preview)
7. Configure the policies and assign to device groups. Intune internally maps the settings to the corresponding OMA-URI paths and delivers them through Policy CSP.

How to update and manage ADMX Templates

Microsoft and other vendors release updated ADMX templates with each major product version. To keep policies current:

• Check for updates quarterly for Windows, Microsoft 365 Apps, and Edge as these change most frequently.
• Back up the existing Central Store before bulk updates by copying it to a time-stamped folder.
• Test in a lab GPO first if updating in a large production environment.
• Document the source version in a README file inside the Central Store.
• Create a simple backup command before updating using:
  Click to copy script

  robocopy "\\domain.local\SYSVOL\domain.local\Policies\PolicyDefinitions" "\\domain.local\SYSVOL\domain.local\Policies\PolicyDefinitions_Backup_2026-05" /E

Troubleshooting common issues

1. ADMX template not showing in Group Policy Editor

   Causes and fixes:

   • ADML file might be missing from the language subfolder. To resolve this, copy the matching .adml file into en-US or your locale.
   • ADMX file might have been placed in a language subfolder by mistake. Ensure that .admx files are placed in the root and not in en-US.
2. Resource '$(string.X) referenced in attribute displayName could not be found

   Cause: The ADML file is missing a string that the ADMX file references. This usually happens with mismatched versions.

   Fix: Download a fresh matched pair of ADMX and ADML files from the vendor and replace both.

3. Namespace conflict errors

   Cause: Two ADMX files declare the same namespace, often when leftover old templates remain after an update.

   Fix: Identify duplicate files using the following PowerShell script and remove them:

   Click to copy script

   powershell Get-ChildItem "\\domain.local\SYSVOL\domain.local\Policies\PolicyDefinitions\*.admx" | Select-String -Pattern "targetNamespace" | Group-Object Line | Where-Object Count -gt 1
4. Templates inconsistent across DCs

   Cause: DFS-R replication is broken or delayed.

   Fix: Run dfsrdiag replicationstate and dfsrdiag backlog to identify replication health, then resolve any DFS-R errors before recopying templates.

5. Central Store not detected by GPMC

   Cause: The folder name is misspelled or in the wrong location.

   Fix: Verify the exact path and ensure it is Policies\PolicyDefinitions, not Policies\Policy Definitions or any variation. Path and folder name are case-insensitive but must match exactly otherwise.

Creating custom ADMX Templates

For in-house applications or registry-based settings without a vendor template, administrators can write custom ADMX files. The minimum required structure is:

FAQs

1. What is the difference between ADMX and ADML files?

ADMX files define policy structure and registry mappings in language-neutral XML, while ADML files contain the display text such as policy names, descriptions, labels for a specific language. Each ADMX file requires at least one matching ADML file to be usable in the Group Policy editor.

2. Where are ADMX templates stored by default?

On individual Windows machines, ADMX files are stored at C:\Windows\PolicyDefinitions, with ADML files in language subfolders like en-US. In a domain, they should be stored in the Central Store at \\<domain>\SYSVOL\<domain>\Policies\PolicyDefinitions.

3. How do I know if my domain is using the Central Store?

Open the GPMC, edit any GPO, and look at the Administrative Templates node. If the Central Store is active, you'll see the text "Policy definitions (ADMX files) retrieved from the central store" displayed at the top of the Administrative Templates node.

4. Can I use ADM and ADMX templates together?

Yes, Windows continues to recognize ADM files, but support is limited and the format is effectively deprecated. ADMX should be the standard for all new deployments, and existing ADM templates should be migrated when possible.

5. Do I need to update ADMX templates on every DC?

No. You only update the Central Store on one DC, and SYSVOL replication via DFS-R distributes the changes to all other DCs automatically.

6. Which ADMX version should I use in a mixed Windows environment?

Always use the newest version available. Newer templates include backward-compatible definitions for older Windows versions.

7. Why don't my new ADMX policies appear in GPMC?

The most common causes are a missing ADML file in the language subfolder, files placed in the wrong location, or SYSVOL replication not yet complete. Verify file placement first, then check replication health.

8. Can I create my own ADMX templates?

Yes. ADMX files are standard XML and can be created in any text or XML editor. Custom templates are useful for managing registry-based settings in in-house applications.