Microsoft has released a new cumulative time zone update for Windows 7 and for all additional Windows platforms. KB2443685 Dec'10 cumulative DST update for Windows operating systems can be accessed for specific information related to the refresh provided on Nov'23rd.
Important "This update supersedes and replaces update 2158563, released in Sep'10. This update also includes additional time zone changes made after update 2158563 was created. If you've already deployed update 2158563, read the descriptions of the specific time zone changes that're addressed in this article to determine whether you must deploy this update immediately. If systems aren't directly affected, you can schedule deployment at the next available opportunity," noted Microsoft.