The 32-bit version of ASP.NET is installed in a 64-bit version of Windows

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2010-04-01

The Microsoft Exchange Best Practices Analyzer analyzes Internet Information Services (IIS) components that are installed on an Exchange server to determine whether the following conditions are true:

  • The server is running a 64-bit version of Windows Server 2003.

  • The 32-bit version of ASP.NET is installed in IIS.

If the Analyzer detects that the 32-bit version of ASP.NET is installed on a computer that is running a 64-bit version of Windows Server 2003, the tool generates an error message.

The ASP.NET component is required to enable Microsoft Office Outlook Web Access. However, if the 32-bit version of ASP.NET is installed together with a 64-bit version of Windows, Outlook Web Access users receive a "Service unavailable" error message when they try to access an Exchange mailbox.

You may have installed the 32-bit version of ASP.NET to meet the requirements of one or more installed programs. For example, an Exchange server may be running Windows SharePoint Portal Services.

To address this issue, run the ASP.NET IIS Registration Tool (Aspnet_regiis.exe) to enable the 64-bit version of ASP.NET in IIS.

To enable the 64-bit version of ASP.NET in IIS 6.0

  1. Open a command prompt, and then move to the following directory:

    %SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727

  2. Type the following command, and then press ENTER:

    aspnet_regiis -r -enable 
    
  3. Exit the command prompt.

For More Information

For more information about the ASP.NET IIS registration tool, see ASP.NET IIS Registration Tool (Aspnet_regiis.exe).

For more information about how to switch between the 32-bit version of ASP.NET and the 64-bit version of ASP.NET, see Microsoft Knowledge Base article 894435, How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit version of ASP.NET 2.0 on a 64-bit version of Windows.