Set default file associations

In Windows 10, the way to set the a default program or a file association is done with a .xml file and a Group Policy setting, when the computer is joined a domain – otherwise you do it manually.


On a reference computer, setup the program and file association as needed and then export the result:

DISM /Online /Export-DefaultAppAssociations:<path>\appAssoc.xml


Edit the .xml file to  contain the settings you wish to apply to your computer clients. It is not recommended that you use it “as-is”.

Below is my default appAssoc.xml file containing Outlook and Internet Explorer as default apps on a computer.

<?xml version="1.0" encoding="UTF-8"?>
  <Association Identifier=".eml" ProgId="Outlook.File.eml.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".hol" ProgId="Outlook.File.hol.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".ics" ProgId="Outlook.File.ics.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".msg" ProgId="Outlook.File.msg.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".oft" ProgId="Outlook.File.oft.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".pst" ProgId="Outlook.File.pst.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".vcf" ProgId="Outlook.File.vcf.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".vcs" ProgId="Outlook.File.vcs.15" ApplicationName="Outlook 2016" />
  <Association Identifier="feed" ProgId="Outlook.URL.feed.15" ApplicationName="Outlook 2016" />
  <Association Identifier="feeds" ProgId="Outlook.URL.feed.15" ApplicationName="Outlook 2016" />
  <Association Identifier="mailto" ProgId="Outlook.URL.mailto.15" ApplicationName="Outlook 2016" />
  <Association Identifier="stssync" ProgId="Outlook.URL.stssync.15" ApplicationName="Outlook 2016" />
  <Association Identifier="webcal" ProgId="Outlook.URL.webcal.15" ApplicationName="Outlook 2016" />
  <Association Identifier="webcals" ProgId="Outlook.URL.webcal.15" ApplicationName="Outlook 2016" />
  <Association Identifier=".htm" ProgId="htmlfile" ApplicationName="Internet Explorer" />
  <Association Identifier=".html" ProgId="htmlfile" ApplicationName="Internet Explorer" />
  <Association Identifier=".mht" ProgId="IE.AssocFile.MHT" ApplicationName="Internet Explorer" />
  <Association Identifier=".mhtml" ProgId="IE.AssocFile.MHT" ApplicationName="Internet Explorer" />
  <Association Identifier=".partial" ProgId="IE.AssocFile.PARTIAL" ApplicationName="Internet Explorer" />
  <Association Identifier=".svg" ProgId="IE.AssocFile.SVG" ApplicationName="Internet Explorer" />
  <Association Identifier=".url" ProgId="IE.AssocFile.URL" ApplicationName="Internet Browser" />
  <Association Identifier=".website" ProgId="IE.AssocFile.WEBSITE" ApplicationName="Internet Explorer" />
  <Association Identifier=".xht" ProgId="IE.AssocFile.XHT" ApplicationName="Internet Explorer" />
  <Association Identifier=".xhtml" ProgId="IE.AssocFile.XHT" ApplicationName="Internet Explorer" />
  <Association Identifier="ftp" ProgId="IE.FTP" ApplicationName="Internet Explorer" />
  <Association Identifier="http" ProgId="IE.HTTP" ApplicationName="Internet Explorer" />
  <Association Identifier="https" ProgId="IE.HTTPS" ApplicationName="Internet Explorer" />
  <Association Identifier="mk" ProgId="IE.HTTP" ApplicationName="Internet Explorer" />
  <Association Identifier="res" ProgId="IE.HTTP" ApplicationName="Internet Explorer" />

If you wish  to add an Adobe product as default PDF reader, Adobe has created a ‘how to’ guide … Read it here


Now copy the .xml file to a network location where all your computers can get a hold on the file, eg. %NETLOGON%\ClientApps\appAssoc.xml

Group Policy

In an relevant Group Policy, go to [Computer Configuration], [Administrative Templates], [Windows Components], [File Explore] and select the [Set a default associations configuration file] setting. Enable it and hereafter enter the path and file name, of the location of the .xml file.

At next reboot the new program and file association should be effective.