No Terminal Server Client access licenses available...Error

[-Wamil-]

We are having several computer systems at my office which all has Windows XP installed on it. We are habitat to use Remote Desktop to lots of ours customers. Suddenly i have got an error message as follows while connecting to one of our customers.
Error : The remote session was disconnected because there are no Terminal Server Client access licenses available for this computer. Please contact the
server administrator.

[Lillebror]

The license obtained for purchase of a Windows XP operating system, allows the use of the system on a machine in no case can it be used for connecting to a server. In this case you need a CAL. There are two types of access license for Windows Server 2003
1) Per Seat : With a per seat license, a CAL is associated with a single user or a single post. This is interesting if a single user has multiple machines, a PC desktop and a laptop for example. Many homeless has two ordis
2) Per Server : With a server license, a CAL is associated with a particular server. You must have at least as many CALs as the maximum number of PCs that can connect to that server. Only Microsoft Windows Server can be purchased this way.
That license by computers. For you to see what license is the most interesting, I think that by buying a Windows Server 2003, are already included with Cal.

[MrChris-]

I can not log into terminal server from a workstation in XP on a server in 2003. I get "no CAL terminal server is available for this computer". A priority, it does not come from the server as any other machine I can connect without problem. Also note that since the post in XP I connect without problem on other servers. Finally, this is not an account problem because the message is the same with different accounts. Sounds like a problem that prevents the client to connect to this server in particular.

[Dr. V]

To use Terminal Server license server, at least one be present. For smaller deployments, both Terminal Server and Terminal Server Licensing service to be installed on the same physical computer. For larger deployments, is recommended to install the Terminal Server Licensing on a different server. Before you install Terminal Server Licensing, the operating system of the license server with the Terminal Server is compliant. Note the following:

• A Windows 2000 license server can no client access licenses to Terminal Server on an operating system of Windows Server 2003 family issue.
• A license server running an operating system of Windows Server 2003 family can issue CALs to terminal servers running Windows Server 2000 or Windows Server 2003 Terminal Server or Windows Server 2000 and Terminal Server in Windows Server 2003 in a mixed environment.

[SalVatore]

After installing the Terminal Server Licensing, you must activate the license server, so the license server can issue permanent client access licenses for Terminal Server clients. If the license server is activated and purchase client access licenses, it offers a safe way to install and issuance of permanent client access licenses to Terminal Services clients. When you activate a license server, temporary client access licenses are issued, that clients can make connections for 90 days to the terminal server.

[Calvin K]

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.