Rather than manually editing the registry on each RDSH server, use Group Policy to enforce licensing settings across all domain-joined session hosts. This reduces configuration drift and simplifies management.
Remote Desktop Services (RDS) Client Access License (CAL) Registry Keys: A Comprehensive Guide
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing . Right-click the key and select Delete . rds cal license registry key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\GracePeriod
If automatic migration fails, you can manually reinstall the CALs using the original license key pack IDs. When prompted during installation, enter the key pack ID to migrate the RDS CALs to the new license server. Rather than manually editing the registry on each
: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM Function : Stores core licensing configuration for RDS including the LicensingMode value:
Ensure your RDS CALs are compatible with the version of Windows Server your users or devices are connecting to. For example, Windows Server 2022 RDS CALs cannot be used to license a Windows Server 2025 session host. Similarly, a Windows Server 2016 version RDLS cannot issue or handle Windows Server 2019 RDS CALs. Right-click the key and select Delete
When an RD Session Host role is installed, Microsoft provides a . During this window, connections are accepted without an active licensing server. Once this grace period expires, connections are blocked until a valid license server is added and CALs are installed.