How to Apply and Activate RDS CALs on Windows Server

Remote Desktop Services lets multiple users connect to a single Windows Server at the same time, but each connecting user or device needs a Client Access Licence (CAL). This guide covers installing the licensing role, activating your licence server and applying your RDS CAL keys. The steps apply to Windows Server 2016, 2019 and 2022.

User CALs vs Device CALs

Choose the licence model before you buy, because the two are not interchangeable once installed:

• User CAL — assigned to a named person, who can then connect from any number of devices. Best for staff who work across a desktop, laptop and phone.
• Device CAL — assigned to a specific machine, which any number of people can use. Best for shift work or shared terminals where several staff use one PC.

Step 1 — Confirm your roles and features

Before applying any keys, check the following are installed and running on your server.

Role:

• Remote Desktop Services

Role services:

• Remote Desktop Licensing
• Remote Desktop Session Host

Features — under Role Administration Tools → Remote Desktop Services Tools:

• Remote Desktop Licensing Diagnoser
• Remote Desktop Licensing Tools

Finally, confirm your server is specified as the Remote Desktop licence server in your Group Policy settings. Without this, session hosts will not find the licence server and connections will fail once the grace period expires.

Step 2 — Open Remote Desktop Licensing Manager

1. Open Server Manager
2. Expand the Tools menu
3. Select Terminal Services → Remote Desktop Licensing Manager
4. Right-click your server and choose Activate Server

Step 3 — Run the Activate Server Wizard

1. Select your connection method. Automatic connection is recommended and works in most environments
2. Fill in your company information as prompted
3. At the end of the wizard, tick Start Install Licenses Wizard now
4. Under License Program, select License Pack (Retail Purchase) and click Next
5. Enter the CAL key supplied in your order email
6. Confirm the activation status now reads Activated

Troubleshooting

The licence server is not activated

If automatic connection fails, your server may not have outbound access to Microsoft's activation service. Check that the server can reach the internet, then re-run the wizard. If it still fails, contact our support team.

Licences installed but users still cannot connect

Run the RD Licensing Diagnoser from Server Manager. The most frequent cause is a mismatch between the licensing mode set in Group Policy and the type of CAL installed — for example, User CALs installed while the policy is set to Per Device.

The grace period has expired

Windows Server allows 120 days of Remote Desktop use before licensing is enforced. Once that lapses, connections are refused until valid CALs are installed and the licence server is activated. The grace period cannot be extended.

Where to buy RDS CALs

We supply genuine Client Access Licences in 5, 10, 20 and 50-unit packs with instant email delivery:

• Windows Server 2019 RDS User CALs
• Windows Server 2019 RDS Device CALs
• Windows Server 2022 RDS Device CALs

You will also need a licensed server operating system. Browse our Windows Server collection, or follow our guide to installing and activating Windows Server 2022 Standard.