Set Custom File Extension For W10

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I haven’t done this yet, but I wanted to take notes for when I do this. Follow this guide to set custom file extensions in Windows 10.

To Resolve:

  1. Setup computer the way you want

  2. Run:

    dism /online /export-defaultappassociations:"C:\Temp\IE-DefaultBrowser.xml"
    • NOTE: DO NOT delete lines from this.

    • This didn’t work, what DID work was:

    Dism /Online /get-DefaultAppAssociations >C:\TEMP\DefaultApps.txt
    • Then just rename to XML.
  3. On new computer:

    Dism.exe /online /import-defaultappassociations:c:\temp\CustomFileAssoc.xml
    • Your file will be copied in C:\Windows\System32 with the following name OEMDefaultAssociations.xml
  4. Or through GPO:

    • Configure the following policy Set a default associations configuration file located in Computer\Policies\Administrative Templates\Windows Components\File Explorer

    • If this group policy is enabled and the client machine is domain-joined, the file will be processed, and default associations will be applied at logon time.

    • To control only some extensions, see the reference.


“Windows 10 – How to configure file associations for IT Pros?”