The update that this article describes changes the time zone data to accommodate daylight saving time (DST) changes in several countries, as outlined in this article. This update also includes other DST-related changes, time zone-related changes, and settings-related changes. Some of these changes have occurred since the products that are listed in the “Applies to” section were originally released.

The update that this article describes is a cumulative update rollup that includes all the changes that were previously released in Microsoft Knowledge Base (KB) articles 928388, 929120, and 933360.

Important: This update supersedes and replaces update 933360, which was released in August 2007. This update also includes additional time zone changes that were signed in to law after update 933360 was created.

If you have already deployed update 933360, read the descriptions of the specific time zone changes that are addressed in this Microsoft Knowledge Base (KB) article to determine whether you must deploy this update immediately. If systems are not directly affected, you can schedule deployment at the next available opportunity.

We recommend that you deploy the most current Windows cumulative time zone update to guarantee the consistency of the time zone database on all systems.

Important: Before you apply the update that is described in this article, be aware of potential issues that may affect Microsoft Outlook. For more information about these issues, click the following article number to view the article in the Microsoft Knowledge Base:

931667 How to address the daylight saving time changes in 2007 by using the Time Zone Data Update Tool for Microsoft Office Outlook

Important:

• If you are running Microsoft Exchange Server in an Information Technology (IT) environment, you must take additional measures to guarantee the correct operation of Exchange Server. For more information about the Exchange daylight saving time (DST) update, click the following article number to view the article in the Microsoft Knowledge Base:
  

  941018 How to address daylight saving time by using the Exchange Calendar Update Tool

• Cumulative time zone updates contain only data that has changed for a specific region or that has been added to maintain parity with other operating system versions. Therefore, if a time zone key has been deleted, some original values may not be restored after you apply the cumulative zone update.

We do not recommend that you delete any registry keys that are related to time zones. On a computer that has incomplete time zone keys, first restore the time zone keys from a known good backup. Then, apply the update.