Rds Cal License Registry Key Review

Last updated: 2025

If your server is failing to recognize installed licenses, it may be because the Licensing Mode

This registry key tells the RD Session Host whether to look for or Per Device CALs.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\GracePeriod The "Timebomb"

RDS session host shows “Per User” mode, but users get a temporary license expiration warning. Check: rds cal license registry key

The most important registry key for an RD Session Host to find its license server is:

Modifying the Windows Registry can cause irreversible system damage if done incorrectly. Always before making changes. Document any values you modify or delete.

Right-click the name of the license server and select Microsoft Learn .

Your RDS host may show event ID 205 or 1004 indicating that no license server was discovered. If Group Policy is not refreshing or DNS discovery fails, manually editing SpecifiedLicenseServers in the registry can bypass discovery. Last updated: 2025 If your server is failing

: Relaunch your Remote Desktop Connection client ( mstsc.exe ) by right-clicking it and selecting Run as Administrator . Running as administrator gives the client permission to recreate the registry key and store the new license. 2. Server-Side Grace Period Registry Key

If your licensing servers are ignored, you can force-feed them to the operating system via this path:

As a general rule: use the registry only when the GUI and PowerShell cmdlets fail. Always back up before making changes, and never edit these keys without fully understanding the dependencies. When used correctly, the registry can save you from a complete RDS rebuild; when misused, it can bring your remote access to a screeching halt.

Running the client as an administrator forces Windows to recreate the deleted registry keys and request a fresh, uncorrupted CAL from the RDS License Server. 4. Configuring RDS Licensing Mode via Registry Always before making changes

: Resetting the GracePeriod registry key is a temporary fix. It does not replace the requirement to purchase and install legitimate RDS CALs.

Save screenshots or .reg exports before each edit.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\Licensing Core

Path: HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\SpecifiedLicenseServers Value: "LS1.domain.local" "LS2.domain.local"