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IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry
On a client computer, when you try to use your mailbox with Outlook 2000, you may receive the following error message:
Unable to display this folder, there are no additional Microsoft Exchange client licenses available.
After you receive the preceding error message, the following event may be logged in the Application Log in Event Viewer on the Small Business Server-based server:
Event ID: 201 Source: LicenseService Type: Error Description: No license was available for user domain name\user name using product MSExchangeIS.
This issue can be caused by either of the following situations:
On the server, the registry setting for the number of licenses for MSExchangeIS is set to an incorrect value.NOTE: If you determine that the registry is incorrectly set, call Microsoft Technical Support for assistance.
: If you determine that the registry is incorrectly set, call Microsoft Technical Support for assistance.On the client computers, Outlook 97/98 was upgraded to Outlook 2000.
NOTE: When Outlook 97/98 is installed on a Microsoft Windows NT Workstation-based client computer, Setup places files in the WINNT\SYSTEM32 folder. On Microsoft Windows 95/98-based and Microsoft Windows Millennium Edition-based client computers, Outlook Setup places files in the Windows\System folder. The following lists include the specific files that are related to this issue:
Outlook 97 Files
Outlook 98 Files
When the client computer is upgraded to Outlook 2000, the preceding files are not upgraded or replaced. Instead, Outlook 2000 places its versions of these files in its own folder in the Program Files folder.
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Stop the License Logging service. To do so, start the Services tool in Control Panel, click the License Logging service, and then click Stop.
Search the client computer for the files that are listed in the "Cause" section of this article. These files are located in the WINNT\SYSTEM32 or Windows\System folders, depending on the client computer's operating system. After you locate these files, rename them to an .old file extension so that only the Outlook 2000 version of these files remains.
Restart the License Logging service. To do so, start the Services tool in Control Panel, click the License Logging service, and then click Start.
For additional information about Event 201 for Exchange Licensing, click the article number below to view the article in the Microsoft Knowledge Base: