Outlook 2007 takes longer than expected to show free/busy information for meeting participants

You open a meeting in Outlook 2007, and then you click Scheduling Assistant in the Show group on the Recurring Meeting tab. After you do this, Outlook 2007 may then take several minutes to show free/busy information for the meeting participants. Additionally, Outlook 2007 may appear to stop responding when it is retrieving the free/busy information.

How to obtain the hotfix

This issue is fixed in the Outlook 2007 Hotfix Package that was released on February 7, 2008. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
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 activate this hotfix, follow these steps:

1. Exit Outlook 2007.
2. Start Registry Editor.
   • In Windows Vista, click Start
     Collapse this imageExpand this image

     
     , type regedit in the Start Search box, and then press ENTER.
     
     
     Collapse this imageExpand this image

     
     If you are prompted for an administrator password or for confirmation, type the password, or click Continue.
   • In Windows XP, click Start, click Run, type regedit, and then click OK.
3. Locate and then right-click the following registry subkey:
   HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\AutoDiscover
4. On the Edit menu, point to New, and then click DWORD Value.
5. Type ExcludeHttpRedirect, and then press ENTER.
6. Right-click ExcludeHttpRedirect, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. On the File menu, click Exit to exit Registry Editor.

This can be caused by a query for free/busy information. The detail thread queries Autodiscover on the CAS server. We use five methods to try to find an AutoDiscover URL, in this order:

1. SCP Object Lookup (on the domain)
2. Attempt HTTPS against Autodiscover.Domain.
3. Attempt HTTPS against Domain.
4. Look for a redirect from HTTP against the Domain.
5. SRV Record (from DNS).

We always try all these methods. There are some configurations for which one or more of these should not be tried because the organization does not use it, and all it does is delay AutoDiscover.

Add a set of registry values, one for each way of trying to obtain the AutoDiscover URL. To disable the method, set the data to 1. The registry subkey where these values are located is as follows: These are all DWORD values, all defaults are zero: If you enable logging, you can use Olkdisc.log file to obtain more detail about these steps in order to troubleshoot. Specifically, it will show you the domains that are tested and any errors encountered.

Note To enable logging, click Tools, click Options, click Other, click Advanced options, and then click Enable logging.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.