Setting the Default PDF Viewer

Both Acrobat and Reader can reside on the same machine, and the default handler can be set in the following ways:

• Set the default handler at install time.

• Configure the installer prior to deployment via the Wizard or command line.

• After a product install, choose Preferences > General > Select Default PDF Handler.

Windows

The steps below apply to all 11.x and later apps deployed on Windows 8 and above.

The problem

Admins often want to reliably set Acrobat and Reader as the default PDF owners on their organization’s desktops. Since Windows 8, it has become more difficult for applications to take ownership of certain filetypes. Even when admins have a method for setting a default handler (described above), once the application is installed end users can change the file type associations via the Control Panel or with Right Click > Open With. Additionally, other applications sometimes force Windows to show an application selection dialog when a user clicks on a file, thereby allowing users to select a different application for that file type. Thus, since Windows 8, admins have little control over file type associations after installing an application.

First step

Both configuration solutions below require an XML file associations file. You can either download the sample file association files which includes all the file types supported by Acrobat and Reader, or you can create your own XML file:

1. Run an elevated command prompt on a machine that has your default application set correctly.

2. Type Dism /Online /Export-DefaultAppAssociations:<XML path>\AppAssoc.xml. This creates an XML file that has all your file types and their current associations.

3. Edit the XML file to include only the file associations that you wish to enforce.

Note

You can create different files for different groups in your organization. For example, one group may use Adobe Reader as the default while another uses Acrobat.

Solution 1: DISM

Deployment Image Servicing and Management (DISM) is a way to enforce file type associations. While it remains difficult to prevent users from selecting alternative default applications, Microsoft addresses this problem by providing DISM as a way for admins to reinstate the defaults when a user logs off and on.

While DISM is a command-line tool that is used to mount and service Windows images before deployment, it can also be used to set file type owners on Windows 8 and above. Admins can use the default application association-servicing commands to import, export, list, and remove the settings that specify which application opens a file based on the file name extension or protocol. Microsoft provides many DISM command line options for performing these steps.

Note

Some admins have been troubleshooting issues here: https://forums.adobe.com/message/10429439#10429439

Solution 2: GPO policy

You can also enforce the filetype via GPO policies. Using Group policy admins can force file associations each time a user logs in. This way even if a user changes the default PDF handler in a particular session or an OS update changes it, the next time the user logs in, it will be changed back to what the admin has specified.

To set the file handler via a GPO:

1. Create or download the XML file as described above.

2. Place the XML on a shared network location or push this XML to all your machine-specific locations via a script. For example, C:\Windows\System32 (do not use a user-specific location).

3. Set the XML configured with your preferences in a Windows Group Policy setting, and enable the setting as follows:

   1. Open up the Group Policy MMC (open a command prompt and type gpedit.msc) on your Server 2012 instance.

   2. Locate the policy under Computer Configuration\Administrative Templates\Windows Components\File Explorer\Set a default associations configuration file. This policy specifies the path for the XML file that can be either stored locally or on a network location. This is a machine-level policy. It is not possible to create user-level policy.

   3. Enable the policy, and specify the location where you have stored the XML file. The corresponding registry entry is HKLM\Software\Policies\Microsoft\Windows\System\DefaultAssociationsConfiguration.

File associations will now be enforced on user logon.

Local Group Policy Editor

Set a file association configuration file

Limitations

1. The end user machine needs to be domain-joined for this method to work.

2. Users can change the file associations during the current session. However, admin settings are reinstated at next logon.

3. As of 5th Feb 2016, it is a known limitation of Windows 10 that when new user is created on the machine after enforcing the GPO Policy, then on first login ownership is not set. However, the correct settings are applied on subsequent logins.

Resetting the default PDF handler

To make Reader the default PDF handler after installing Acrobat, find and run ADelRCP.exe in elevated mode. ADelRCP.exe is Acrobat’s PDF handler program for Windows.

Affected ProgIDs for various products

Reader (Continuous)

File Type	ProgID
.pdf	AcroExch.Document.DC
.pdfxml	AcroExch.pdfxml
.acrobatsecuritysettings	AcroExch.acrobatsecuritysettings
.fdf	AcroExch.FDFDoc
.xfdf	AcroExch.XFDFDoc
.xdp	AcroExch.XDPDoc
.pdx	PDXFileType
.api	AcroExch.Plugin
.secstore	AcroExch.SecStore

Acrobat (Continuous)

File Type	ProgID
.pdf	Acrobat.Document.DC
.pdfxml	Acrobat.pdfxml
.acrobatsecuritysettings	Acrobat.acrobatsecuritysettings
.fdf	Acrobat.FDFDoc
.xfdf	Acrobat.XFDFDoc
.xdp	Acrobat.XDPDoc
.pdx	PDXFileType
.api	Acrobat.Plugin
.secstore	Acrobat.SecStore
.sequ	Acrobat.Sequence
.rmf	Acrobat.RMFFile
.bpdx	AcrobatBPDXFileType

Reader (Classic)

File Type	ProgID
.pdf	AcroExch.Document.2020 (version 2020 only)
.pdf	AcroExch.Document.2017 (version 2017 only)
.pdf	AcroExch.Document.2015 (version 2015 only)
.pdfxml	AcroExch.pdfxml
.acrobatsecuritysettings	AcroExch.acrobatsecuritysettings
.fdf	AcroExch.FDFDoc
.xfdf	AcroExch.XFDFDoc
.xdp	AcroExch.XDPDoc
.pdx	PDXFileType
.api	AcroExch.Plugin
.secstore	AcroExch.SecStore

Acrobat (Classic)

File Type	ProgID
.pdf	Acrobat.Document.2020 (version 2020 only)
.pdf	Acrobat.Document.2017 (version 2017 only)
.pdf	Acrobat.Document.2015 (version 2015 only)
.pdfxml	Acrobat.pdfxml
.acrobatsecuritysettings	Acrobat.acrobatsecuritysettings
.fdf	Acrobat.FDFDoc
.xfdf	Acrobat.XFDFDoc
.xdp	Acrobat.XDPDoc
.pdx	PDXFileType
.api	Acrobat.Plugin
.secstore	Acrobat.SecStore
.sequ	Acrobat.Sequence
.rmf	Acrobat.RMFFile
.bpdx	AcrobatBPDXFileType

Locking the PDF viewer

Admins can prevent end users from changing the setting by using the HKLM feature lockdown preference DisablePDFHandlerSwitching.

Note

This does not prevent users from changing PDF ownership using Windows Explorer.