Microsoft KB Archive/187614

= Removing Terminal Server licenses from an RDP client =

Article ID: 187614

Article Last Modified on 10/11/2007

-

APPLIES TO


 * Microsoft Windows NT Server 4.0, Terminal Server Edition
 * Microsoft Windows 2000 Service Pack 1
 * Microsoft Windows 2000 Service Pack 2
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Service Pack 2
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003 Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, 64-Bit Datacenter Edition
 * Microsoft Windows Server 2003, 64-Bit Enterprise Edition
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems
 * Microsoft Windows Server 2003, Datacenter x64 Edition
 * Microsoft Windows Server 2003, Enterprise Edition
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Windows Vista Business
 * Windows Vista Enterprise
 * Windows Vista Home Basic
 * Windows Vista Home Premium
 * Windows Vista Starter
 * Windows Vista Ultimate

-



This article was previously published under Q187614



Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



SUMMARY
If an unlicensed client connects to a Terminal Server for the first time, the Terminal Server issues the client a temporary Terminal Server Client Access License (CAL) token. After the user has logged into the session, the Terminal Server instructs the License Server to mark the issued temporary Terminal Server CAL token as being validated. The next time the client connects, an attempt is made to upgrade the validated temporary Terminal Server CAL token to a full Terminal Server CAL token. If no license tokens are available, the temporary Terminal Server CAL token will continue to function for 90 days. The license is stored in the client's registry.

Thirty-two bit RDP clients store their license under the key HKEY_LOCAL_MACHINE\Software\Microsoft\MSLicensing.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To clean the client's license cache, just delete this key and its subkeys. The next time the client connects to the server, it will obtain another license.

For 16-bit RDP clients, run regedit /v. Then delete the keys under "\Software\Microsoft\MSLicensing" to clean the client's license cache. You can also delete the BIN files from \Windows\System\Regdata.

The RDP client for Macintosh stores the license in a file on the local computer in the folder hierarchy under /users/Shared/Microsoft/RDC Crucial Server Information/. To clean the Macintosh client's license cache, delete the contents of this folder. The client will try to obtain a new license from the server the next time that it connects.

If you delete the  subkey on a client that is running Windows Vista or a later version, later attempts to connect to a Terminal Server may fail. Also, you receive the following error message:

An Error occurred in the Licensing Protocol

To resolve this problem, right-click the Remote Desktop Connection shortcut, and then click Run as Administrator. By default, the remote desktop connection runs as a user with the lowest user permissions. By default, a restricted user does not have permission to write registry entries to HKEY_LOCAL_MACHINE. Therefore, attempts to rewrite the MSLicensing key fail. Starting Remote Desktop Connection with administrative credentials provides the permissions that are necessary to write the needed registry keys.

Keywords: kbinfo KB187614

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.