Windows Server 2016 Datacenter

To activate a Remote Desktop license server by telephone: On the license server, open Remote Desktop Licensing Manager -> click Start, point to Administrative Tools, point to Remote Desktop Services, and then click Remote Desktop Licensing Manager. Right-click the license server that you want to activate, and then click Activate Server. The Activate Server Wizard starts. Click Next. On the Connection Method page, in the Connection method list, select Telephone, and then click Next. On the Country or Region Selection page, click your country/region, and then click Next to view the appropriate telephone number to call. Call Microsoft by using the telephone number that is displayed on the License Server Activation page, and then provide the Microsoft customer support representative with the Product ID that is displayed on your screen. The representative will also ask you to provide your name and the name of your company. The representative processes your request to activate the license server and creates a unique ID for your license server. On the License Server Activation page in the Activate Server Wizard, type the license server ID that the representative provides, and then click Next. Your license server is activated. On the Completing the Activate Server Wizard page, do one of the following: To install Remote Desktop Services client access licenses (RDS CALs) onto your license server, ensure that the Start Install Licenses Wizard now checkbox is selected, click Next, and then follow the instructions. To install RDS CALs later, clear the Start Install Licenses Wizard now check box, and then click Finish. Make sure that you are trying to redeem the code on the same version of the program.