Rds Cal License Registry Key Fix May 2026

Managing RDS CALs via the Windows Registry is typically done to define licensing servers, set licensing modes, or reset the 120-day grace period. While Group Policy is the preferred management tool, these registry keys provide direct control over how a Session Host interacts with the License Server.  Core RDS Licensing Registry Keys 

The report clarifies the distinction between the License Server Registry (where issued licenses are stored) and the Client Device Registry (where received tokens are cached). rds cal license registry key

Cause: Per User CALs are not auto-applied — they require tracking in AD or manual installation. Registry only stores the mode preference.
Fix: Ensure Per User CALs are actually installed on the license server (RD Licensing Manager → Install Licenses). Managing RDS CALs via the Windows Registry is

RDS configuration is primarily handled within HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\. Cause: Per User CALs are not auto-applied —

The Secret Code: Setting this to 2 tells the server to look for Per Device CALs; setting it to 4 switches it to Per User. The Address Book (SpecifiedLicenseServers):

Registry Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\Licensing Core Value: LicensingMode (DWORD) — Same values as above.

The RD Licensing Diagnoser shows a "No license server available" error despite correct settings.