How to Set the Forms-Based Authentication Private Computer Cookie Time-Out Value

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.


Applies to: Exchange Server 2007, Exchange Server 2007 SP1, Exchange Server 2007 SP2, Exchange Server 2007 SP3

Topic Last Modified: 2007-03-20

This topic explains how to configure the cookie time-out values for private computers by using forms-based authentication on a Microsoft Outlook Web Access virtual directory in Microsoft Exchange Server 2007. Private computers are also known as trusted computers.

It is important that you warn users of the risks that are associated with selecting the This is a private computer option. A user should select This is a private computer only if the user is the sole operator of the computer, and the computer complies with your organization's security policies.

To perform the following procedures, the account you use must be delegated the Exchange Server Administrator role and membership in the local Administrators group for the target server.

For more information about permissions, delegating roles, and the rights that are required to administer Exchange Server 2007, see Permission Considerations.

Also, make sure that the Outlook Web Access virtual directory is configured to use forms-based authentication.

Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

  1. On the Exchange Client Access server, log on by using your Exchange administrator account, and then start Registry Editor (regedit).

  2. In Registry Editor, locate the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange OWA

  3. On the Edit menu, point to New, and then click DWORD Value. In the details pane, name the new value PrivateTimeout.

  4. Right-click the PrivateTimeout DWORD value, and then click Modify.

  5. In Edit DWORD Value, under Base, click Decimal.

  6. In the Value Data box, type a value in minutes between 1 and 43,200 for a maximum of 30 days. Click OK.

    You must restart Internet Information Services (IIS) by using the command iisreset/noforce for these changes to take effect.

  1. Open the Microsoft Command Shell and run the following command to set the private computer cookie time-out value:

    set-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\MSExchange OWA' -name PrivateTimeout -value <amount of time> -type dword
    You must restart IIS is by using the command iisreset/noforce for these changes to take effect.
  2. Run the following command to view the private computer cookie time-out value:

    get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\MSExchange OWA' -name PrivateTimeout