The most recent update at the time of publication is December 2008 cumulative time zone update for Microsoft Windows operating systems.
Out of the box, XP and the new DST changes don’t get along. For a single machine, I found the most straight-forward way to update your machine is through TZEdit.
My system clock on my XP system will not stay advanced 1 hour for Daylight Savings Time.
After about 1 hour it will jump back to one hour earlier.
Microsoft Windows time service keeps track of Daylight Savings Time (DST) and can be set to automatically adjust your computer's clock to reflect the time changes.
With the recent changes to DST windows users must apply a patch to allow the system to update the time on the proper dates. Accept the License Agreement by selcting the "I Agree" radio button. The update application will now check to see if the patch needs to be applied.Windows update will install a patch that reflects the new daylight times, on Windows XP and 2003 systems.