XCLN: Disabling Calendar Caching in Outlook 98 (237856)


The information in this article applies to:

  • Microsoft Outlook 98
This article was previously published under Q237856
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

SUMMARY

Companies that have many users who rely heavily on calendar sharing and who have delegate or multiple delegate relationships may opt to disable the calendar caching feature in Outlook 98 as described in the following Microsoft Knowledge Base article:

185237 OL98: (CW) Outlook Speed Enhancement to Calendar Folder Access

Some of the most common issues affecting these users who rely on calendar sharing and who have delegate or multiple delegate relationships are:
  • Duplicate appointments.
  • Dismissed reminders resurfacing.
  • Conflicting appointments.
  • Missing calendar items.

MORE INFORMATION

For example, consider the following issue of duplicate and conflicting meetings.

If the manager's client is configured to use an .ost file for calendar caching (this is the default with Outlook 98), and both the manager's client and the delegate clients are configured to process requests and responses on arrival, duplicate and conflicting meetings are expected.

When the delegate client receives the meeting request, it looks at the manager's calendar on the server. The delegate client does not see a meeting on this manager's server calendar, so the delegate client processes the meeting request and tentatively schedules the meeting.

When the manager's client receives the meeting request, it looks at the cached copy of the calendar in the local .ost file. The manager's client does not see the meeting scheduled, so the manager's client processes the meeting request and tentatively schedules the meeting. Later, when the .ost file is synchronized with the server, the meeting on the server is pulled into the .ost file, the appointment in the .ost file is pushed to the server, and duplicate meetings are created. This is expected behavior for the given client configuration.

This behavior does not occur in either of the following two circumstances:
  • If the manager's configuration is changed to not use the calendar caching feature of Outlook 98. -or-

  • If the delegate disables the Process requests and responses on arrival option.
There are two ways to address and resolve this issue. Outlook development recommends that you use a registry entry to disable calendar caching. The options are:
  • Disable the Process requests and responses on arrival option on the delegates' computer.

    The side effect of this option is that the delegates do not automatically process meeting requests for themselves.
  • Add the registry setting NoOST, and set it to 2 or 3. This disables the use of the .ost file for caching a local copy of the calendar.
The file that allows you to set the registry key to 2 or 3 as described above is the Outllib.dll file. This file can be obtained by installing the Arch98en.exe file from the following location:

http://office.microsoft.com/downloads/9798/arch98en.aspx

You can also contact Microsoft Product Support Services for the latest version of this file.

NOTE: The Outllib.dll file also fixes the issue described in the following Microsoft Knowledge Base article:

150827 Outlook 98: (CW) Synchronization Properties Tab is Missing

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.

Install the Outllib.dll file, and then make the registry change to add the NoOST option 2 or 3 to the computer of the user whose calendar is being shared or managed by other delegates. To do so:
  1. Quit Outlook.
  2. Click Start, click Run, type regedit, and then click OK.
  3. Click to select the following registry entry:

    HKEY_CURRENT_USER\Software\Microsoft\Office\8.0\Outlook

  4. If the Outlook key has a subkey named OST with a NoOST entry, skip to step 8. Otherwise, right-click the Outlook key, and on the shortcut menu, click New, and then click Key.
  5. Type OST as the name for the new key, and press the ENTER key.
  6. Right-click the new OST key, and on the shortcut menu, click New, and then click DWORD Value.
  7. Type NoOST as the name for the new entry, and press the ENTER key.
  8. Right-click the NoOST entry, and on the shortcut menu, click Modify.
  9. Type one of the following values: 2 = An offline store is NOT set up by default and the user is NOT allowed to enable offline access and use the offline store. The options in the Microsoft Exchange Server properties are not available.

    NOTE: This is a good option for desktop users who do not have use of an offline store.

    3 = An offline store is NOT set up by default and the user is allowed to enable offline access and use the offline store.

  10. Delete all existing OSTs before you start Outlook again.

Additional NoOST Options

0 = An offline store is set up by default and used for calendar caching. Also, the user is allowed to enable offline access and use the offline store.

This is the same as the absence of the OST key and NoOST entry.

1 = An offline store is set up by default and used for calendar caching. However, the user is NOT allowed to enable offline access and use the offline store. The options in the Microsoft Exchange Server properties are not available.

Possible Scenarios

User 1. Desktop user with Outlook 98. This user has an .ost file created upon first use of Outlook. This file is resident on the desktop computer and up to date.

User 2. Laptop user with Outlook 98. This user has an .ost file created upon first use of Outlook. This user may not have an offline store configured and does not have use of an offline store. This user does not want or need offline use.

User 3. Laptop user with Outlook 98. This user has an .ost file created upon first use of Outlook. This user may have configured an offline store and synchronizes his or her folders with his or her .ost file. This .ost file is available for offline use.

Recommendations

NOTE:The updated Outllib.dll file must be in place for these settings to work properly and all .ost files must be deleted from the computer.

User 1. Implement NoOST=2 in the registry. The NoOST=2 option disables calendar caching. Nothing else needs to be done with this user's computer.

User 2. Implement NoOST=2 in the registry. The NoOST=2 option disables calendar caching. Nothing else needs to be done with this user's computer.

User 3. Implement NoOST=3 in the registry. The NoOST=3 option disables calendar caching. Nothing else needs to be done with this user's computer.
Modification Type:MinorLast Reviewed:11/3/2004
Keywords:kbdownload kbinfo KB237856
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