Windows OS is affected and needs to be updated either with a hotfix or via a manual registry update
In case you’re interested in the hotfix for a product that is outside Mainstream Support, the per-hotfix price for Extended Support for DST hotfixes has been reduced substantially. Please contact your Technical Account Manager or your MS Account Executive for details.
Guidance for manually updating OS http://support.microsoft.com/kb/914387.
Support WebCast: Deploying Microsoft Windows 2000 updates for daylight saving time changes
Most applications get their time information from the OS, so most applications are not affected
Exchange servers need to have the Exchange CDO patch applied
Outlook versions prior to 2007 must have appointments updated after the OS patch is applied.
An Outlook Time Zone Data Update Tool is being released in January to enable updating the appointments (this must be run in a user context, so it cannot be distributed through Windows Updates). It will support data created/consumed by Outlook 2000, Outlook 2002, and Outlook 2003 and is being tested on Windows 2000, Windows XP SP2, Windows Server 2003, and Vista.
A server-side tool will also be released that can be run by Exchange administrators and automatically updates all chosen client mailboxes without any user interaction.
Please read KB931667 for details about the Outlook Time Zone Data Update Tool and implications of the order in which you patch systems and update calendars.
LIST OF DST 2007 RELATED KB ARTICLES
Preparing for daylight saving time changes in 2007(main DST site): http://www.microsoft.com/windows/timezone/dst2007.msp
“Manual Method” for Windows: http://support.microsoft.com/kb/914387
Addressing daylight saving time using the Outlook Time Zone Data Update Tool
Windows Mobile: http://support.microsoft.com/?id=923953
Dynamics CRM 3.0 http://support.microsoft.com/kb/925874
Entourage (Mac) 2004:
Windows CE: http://support.microsoft.com/?id=923027