Activation of Windows Server 2025 RDS 50 Users

Activating the remote desktop service in Windows Server 2025 for the RDS 50 User CAL package is necessary to legally and correctly provide remote desktop or applications to multiple users in your company. Simply installing the Remote Desktop Services role is not enough. You also need to activate the RDS licence server, add the purchased licences, and specify the server that will issue them.

In this guide, we show you how to perform the activation step by step, how to check the correctness of the configuration, and what to do when the most common problems occur. If you need support during configuration, write to us: [email protected].

Step by Step

1. Install the required roles for RDS

On a server with Windows Server 2025, open Server Manager and then go to Add Roles and Features. If the RDS environment is not yet configured, install at least:

• Remote Desktop Licensing
• Remote Desktop Session Host

In more advanced deployments, you can also install additional roles, but for license activation, it is crucial to start the RDS licensing service.

After installation, restart the server if the system requires it.

2. Run the Remote Desktop Licensing Manager

Open the tool:

Remote Desktop Licensing Manager

You can start it from the Start menu or through Server Manager > Tools. On the left side, your license server should be visible. If it is greyed out or marked with a warning, you need to activate it first.

3. Activate the RDS license server

Right-click the server name and select Activate Server. The activation wizard will start.

The most commonly chosen method is Automatic connection, as it allows for the fastest connection to the Microsoft activation service. In the next steps, fill in your company's details, such as name, country, and email address. After completing the wizard, the license server should change its status to active.

If the server does not have internet access, you can also use activation via a browser or phone, but in corporate environments, automatic activation remains the most convenient.

4. Install RDS 50 User CAL licenses

After activating the license server, you will have the option to add a CAL package. If the wizard does not start automatically, right-click the server and select Install Licenses.

In the wizard, select the appropriate licensing program according to your purchase. Then, enter the licensing data or the key required by the supplier. For the RDS 50 User CAL variant, after successful installation, the console should display a pool of licenses assigned to users.

It is essential to install licenses that match their intended use:

• Per User, if you purchased RDS 50 User CAL
• not Per Device, if licenses are assigned to users

This distinction is crucial for correct license calculation and compliance.

5. Set the licensing mode to Per User

Installing CAL alone is not enough. You must also specify the mode in which the RDS session host should operate.

Open: Server Manager > Remote Desktop Services or use local group policies: Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Licensing

Configure the two most important options:

• Set the Remote Desktop licensing mode to Per User
• Use the specified Remote Desktop license servers and enter the name of your license server

After saving the settings, run gpupdate /force or restart the server.

6. Verify communication between the session host and the license server

The RDS session host must see the license server by name and through the network. Ensure that:

• DNS resolves the server name correctly
• the system firewall does not block communication
• RDS services operate without errors
• the system clock is synchronized

If you encounter problems with detecting the license server, it's also worth checking the Event Viewer.

If you need help or have questions, please contact us at [email protected] or call 00 800 121 1654.

Checking

After completing the configuration, it's worth confirming that everything is working correctly.

The simplest method is to open the Remote Desktop Licensing Diagnoser. This tool shows whether the session host has the correct licensing mode set and whether it can see an active license server. If the configuration is correct, there should be no critical warnings about missing CALs or unconfigured licensing modes.

Additionally, in Remote Desktop Licensing Manager, you can check if the RDS 50 User CAL package is visible on the list and whether the server has an active status.

In practice, it's also a good idea to perform a test login via Remote Desktop with a domain user account and check if the session starts without any license-related error messages.

Problems

The most common problem is an inconsistent licensing mode. If User CAL is installed, but the session host is set to Per Device, the server will report errors despite the licenses being correctly added. In such a situation, you should change the mode to Per User.

Another common problem is the lack of a specified license server. Even an activated server with installed CALs will not work if the Session Host does not have it entered in the configuration or group policies.

There is also a situation where licenses have been added correctly, but the diagnostics still show warnings. Sometimes this is due to a delay in updating policies or the need to restart RDS services. In such cases, it's worth running gpupdate /force, restarting the server, and checking the event logs.

If the problem concerns the activation of the license server itself, the cause may be a lack of internet access, proxy blocking, or traffic filtering by a firewall. In such cases, alternative activation or contact with the license provider may be helpful.

FAQ

Does RDS 50 User CAL mean 50 simultaneous connections?

Not always directly. User CAL means permission for 50 users, not 50 specific devices. In practice, each authorized user can connect from different computers, as long as the environment is properly configured and the number of licenses corresponds to the actual number of people using RDS.

Can I activate RDS licenses on a different server than the session host?

Yes. The license server can operate separately. In such a case, you just need to correctly specify it in the Remote Desktop Session Host settings so that the session host knows where to obtain licenses.

What to do if I still see a message about missing licensing after installing licenses?

First, check the Per User mode, the license server name, and the result in Remote Desktop Licensing Diagnoser. If the settings are correct, update the policies, restart the services, or the entire server. If the problem still occurs, contact us at [email protected].

If you need help with activating Windows Server 2025 RDS 50 User CAL, verifying configuration, or selecting the correct license, please contact us: [email protected] or call 00 800 121 1654.