This week is back to the management capabilities for Windows devices. More specifically, it’s all about managing settings via third-party ADMX-files by using Microsoft Intune. That’s something that used to be a big task and now turned in to a relatively simple action. This blog contains posts around that subject that details the process of ingesting third-party ADMX-files and configuring the related settings. The good thing is that those posts still have value, as the underlying process hasn’t changed. Microsoft did, however, drastically simplify the process for importing third-party ADMX-files and configuring the different settings. This post will describe the new simplified process of working with third-party ADMX-files and provides some details around the configuration that are good to know.
Important: At the moment of writing, the feature of importing third-party ADMX-files is in public preview.
Importing third-party ADMX-files
Before actually looking at the actions for importing third-party ADMX-files, it’s important to be familiar with the current limitations of this feature. Those limitations will help with determining the usage of the feature.
- A maximum of 10 ADMX-files can be imported (each being 1MB or smaller)
- Each ADMX-file only supports a single language (each can also only be combined with a single ADML-file)
Important: At the moment of writing, only en-us
ADML-files are supported.
Once being familiar with the current limitations of this feature for importing third-party ADMX-files, it’s time to look at the required actions to actually perform the import. With that it’s important to know that any dependencies of a third-party ADMX-file, should be imported before importing the third-party ADMX-file that contains the required settings. A good example for that is the configuration of Mozilla Firefox. That can be achieved via settings in the firefox.admx
file, which depends on the mozilla.admx
file. That makes the configuration of Mozilla Firefox a great example to walk through the process of importing third-party ADMX-files. The following steps walk through that process.
Important: At the moment of writing, the combobox setting type isn’t supported
Note: Before starting with these actions make sure to first download the required ADMX-files and ADML-files.
- Open the Microsoft Endpoint Manager admin center portal and navigate to Devices > Configuration profiles
- On the Import ADMX tab, select Import to start the process of importing the ADMX-file and ADML-file
- On the ADMX file upload page, as shown in Figure 1, provide the following information and click Next
- ADMX file: Select the
mozilla.admx
file to import - ADML file for the default language: Select the
mozilla.adml
file to import - Specify the language of the ADML file: At this moment English is selected and grayed out
- ADMX file: Select the

- On the Review + create page, click Create
- Once the Status is Available, walk through step 2-4 for the
firefox.admx
file and thefirefox.adml
file
When working on importing the required ADMX-files and ADML-files, the challenge will be in keeping them up-to-date. That’s because when uploading an ADMX-file with settings that are already imported, the upload will fail. That includes a new version of an ADMX-file that contains the same settings as the existing ADMX-file. That leaves actually replacing the existing ADMX-file and creating a new ADMX-file with only the new settings, as the options for updating existing ADMX-files.
Configuring settings of the imported third-party ADMX-files
After importing the different required third-party ADMX-files and ADML-files, the available settings within those ADMX-files become available for configuration via Microsoft Intune. That can be achieved by using the new configuration template named Imported Administrative templates. The following steps walk through the process of configuring different settings of Mozilla Firefox. That includes the obvious and visual setting to configure a homepage.
- Open the Microsoft Endpoint Manager admin center portal and navigate to Devices > Windows > Configuration profiles
- On the Windows | Configuration profiles page, click Create profile
- On the Create a profile blade, provide the following information and click Create
- Platform: Select Windows 10 and later
- Profile type: Select Templates > Imported Administrative templates
- On the Basics page, provide a unique name and click Next
- On the Configuration settings page, as shown in Figure 2, configure the required settings and click Next

- On the Scope tags page, configure the require scope tags and click Next
- On the Assignments page, configure the required assignment and click Next
- On the Review + create page, verify the configuration and click Create
Verifying the configuration results
Once the configurations are in place, it’s time to actually verify the applied configuration settings. That can be achieved by actually looking at the configuration of the Mozilla Firefox browser, by looking at the Registry Editor and also by looking at the Settings app (as shown below in Figure 3). Those different locations can be used to see the following information:
- The Mozilla Firefox browser clearly shows that the configurations is applied and managed by the organization.
- The Registry Editor clearly shows the configurations settings that are applied, in a similar fashion as with configuring Group Policy settings (it also contains information about the ingested ADMX-files and settings).
- The Settings app provides an overview of the applied configurations, in a similar fashion as with manually ingesting ADMX-files and configuring them.

More information
For more information about managing third-party ADMX-files, refer to the following docs.
- Use ADMX templates on Windows 10/11 devices in Microsoft Intune | Microsoft Learn
- Import custom and third party partner ADMX templates in Microsoft Intune | Microsoft Learn
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Hello Peter,
I have imported the ADMX and ADML templates thorugh intune “Import ADMX” functionality successfully. But deleting the ADMX templates is failing and the templates does not get removed even after deleting the configuration profiles related to ADMX. Any idea know how to delete this imported templates?
Warm Regards Mayur
Hi Mayur,
I’m seeing the same. The best would probably be to contact Microsoft Intune support.
Regards, Peter
Hi Peter,
I think it’s worth to mention that you can only import 10 admx templates, afterwards you get the message “Limit reached”. This limitation is documented by Microsoft.
The crazy thing is that there seems to be no way to delete templates (as Mayor mentioned above), so it’s really important to think in advance which admx files to include.
/Frank
Hi Frank,
Apologies for the late reply, as I was enjoying my vacation. That is correct. I think you should be able to achieve some deletion via Microsoft.
Regards, Peter
Hi Peter, I left a comment here yesterday regarding the missing option to remove GPOs and realized later that I was wrong: You find the delete option under the three dots (‘breadcrumps’) on the right side. However, the attempt to a delete a template didn’t succeed, status is ‘Removal failed’, so same experience as Mayur described.