# Set Default File Associations for Your Users in Amazon WorkSpaces Applications
<a name="customize-fleets-set-default-file-associations"></a>

The associations for application file extensions are set on a per-user basis and so are not automatically applied to all users who launch WorkSpaces Applications streaming sessions. For example, if you set Adobe Reader as the default application for .pdf files on your image builder, this change is not applied to your users. 

**Note**  
The following steps apply to Windows fleets only.

**Note**  
The following steps must be performed on an image builder that is joined to an Active Directory domain. In addition, your fleet must be joined to an Active Directory domain. Otherwise, the default file associations that you set are not applied.

**To set default file associations for your users**

1. Connect to the image builder on which to set default file associations and sign in with a domain account that has local administrator permissions on the image builder. To do so, do either of the following: 
   + [Use the WorkSpaces Applications console](managing-image-builders-connect-console.md) (for web connections only)
   + [Create a streaming URL](managing-image-builders-connect-streaming-URL.md) (for web or WorkSpaces Applications client connections)
**Note**  
If your organization requires smart card sign in, you must create a streaming URL and use the WorkSpaces Applications client for the connection. For information about smart card sign in, see [Smart Cards](feature-support-USB-devices-qualified.md#feature-support-USB-devices-qualified-smart-cards).

1. Set default file associations as needed.

1. Open the Windows command prompt as an administrator.

1. At the command prompt, type the following command to export the image builder file associations as an XML file, and then press ENTER: 

   `dism.exe /online /export-DefaultAppAssociations:c:\default_associations.xml`

   If you receive an error message stating that you cannot service a running 64-bit operating system with a 32-bit version of DISM, close the command prompt window. Open File Explorer, browse to C:\$1Windows\$1System32, right-click cmd.exe, choose **Run as Administrator**, and run the command again.

1. You can use either Local Group Policy Editor or the GPMC to set a default associations configuration file:
   + Local Group Policy Editor:

     On your image builder, open the command prompt as an administrator, type `gpedit.msc`, and then press ENTER. 

     In the console tree, under **Computer Configuration**, expand **Administrative Templates**, **Windows Components**, and then choose **File Explorer**.
   + GPMC: 

     In your directory or on a domain controller, open the command prompt as an administrator, type `gpmc.msc`, and then press ENTER.

     In the left console tree, select the OU in which you want to create a new GPO, or use an existing GPO, and then do either of the following:
     + Create a new GPO by opening the context (right-click) menu and choosing **Create a GPO in this domain, Link it here**. For **Name**, provide a descriptive name for this GPO.
     + Select an existing GPO.

     Open the context menu for the GPO, and choose **Edit**.

     Under **User Configuration**, expand **Policies**, **Administrative Templates**, **Windows Components**, and then choose **File Explorer**. 

1. Double-click **Set a default associations configuration file**.

1. In the **Set a default associations configuration file properties** dialog box, choose **Enabled**, and do one of the following:
   + If you are using Local Group Policy Editor, enter this path: `c:\default_associations.xml`. 
   + If you are using the GPMC, enter a network path. For example, `\\networkshare\default_associations.xml`.

1. Choose **Apply**, **OK**.

1. Close Local Group Policy Editor or the GPMC.

1. On the image builder desktop, open Image Assistant.

1. Follow the necessary steps in Image Assistant to finish creating your image. For more information, see [Tutorial: Create a Custom WorkSpaces Applications Image by Using the WorkSpaces Applications Console](tutorial-image-builder.md).

   The file associations that you configured are applied to the fleet instances and user streaming sessions that are launched from those instances.