How to Set Reader or Acrobat as the Default PDF App in an RDS Farm
Question details
Users in a shared RDS farm experience issues where Adobe Acrobat repeatedly becomes the default PDF application, prompting trial and license messages for users who should be using Adobe Reader.
- Product
- Adobe Acrobat and Reader
- Device & OS
- Windows Server RDS
- Scenario
- Managing default PDF application settings for different user groups in a shared Remote Desktop Services (RDS) environment.
- Observed behavior
- Acrobat takes over as the default PDF app, causing unlicensed users to receive trial and license expiration prompts instead of opening files in Reader.
Ensure you have administrative privileges to the RDS environment, access to group policy management, and permission to deploy third-party utilities like SetUserFTA on your network.
Use SetUserFTA to Assign Default PDF Apps by Security Group
The most reliable method to prevent Windows from resetting file associations in an RDS farm is using SetUserFTA in a logon script, which correctly handles Windows hash values.
In modern Windows operating systems, a hash system is used for file associations to prevent unauthorized apps from hijacking defaults. Because of this, traditional registry edits or simple scripts fail to change the default PDF handler.
To assign PDF file associations by security group dynamically without triggering the Windows reset behavior, you must use a specialized tool like SetUserFTA that calculates and writes the correct hash.
Obtain the SetUserFTA tool and place the executable in a shared network location (such as the NETLOGON folder) that is accessible to all users in the RDS farm.
Determine the Active Directory security groups for your users. You will need to distinguish between the group that is licensed for Acrobat Pro and the group that should only use Adobe Reader.
Write a batch (.bat) or PowerShell (.ps1) script that checks the user's group membership upon logging into the RDS session.
In your script, add the SetUserFTA commands. For Acrobat Pro users, run 'SetUserFTA.exe .pdf AcroExch.Document.DC'. For Adobe Reader users, run 'SetUserFTA.exe .pdf AcroExch.Document.11' (or the specific ProgID for your Reader version).
Open Group Policy Management, create or edit a GPO applied to your RDS users, and assign your script under User Configuration > Policies > Windows Settings > Scripts (Logon/Logoff).
Simplify Your RDS Environment with WPS Office
Instead of battling Windows default app resets and split-license headaches between Reader and Acrobat, deploy WPS Office as your standard PDF handler. It provides powerful reading and editing capabilities in one lightweight, unified application that is easy to manage in virtualized environments.
- 1. Install WPS Office: Deploy the WPS Office installer across your RDS environment servers.
- 2. Set Default App: Use Group Policy or your preferred default association tool to set WPS Office as the default handler for the .pdf extension for all users.
- 3. Open PDFs Seamlessly: Users can now open, view, and annotate PDF files from a single, fast-loading application without mismatched licensing prompts.
Frequently Asked Questions
Why does Adobe Acrobat keep overriding Adobe Reader as the default PDF app?
In a shared environment, application updates, background services, or Windows default behaviors might trigger file association resets. If Acrobat is installed, it frequently reasserts itself as the default handler, causing unlicensed users to get trial prompts.
What is SetUserFTA and why do I need it?
SetUserFTA is a command-line utility that bypasses the Windows 10/11 hash requirement for file associations. It allows administrators to force file types like .pdf to open in specific programs without Windows recognizing the change as unauthorized and resetting it.
Can I use Group Policy (GPO) default associations XML instead?
While standard GPO has an 'OEM Default Associations' XML policy, it applies system-wide and cannot dynamically target specific user security groups within the same RDS server. SetUserFTA is required for per-user or per-group targeting.
