My Windows XP SP2 has changed the summer time one week earlier; I don't know if the connecting to the Cisco Router that had the old summer time and my laptop had sync with it when I used the VPN. However, I fixed the Cisco router's summer time settings matched with the new summer time and I manually fixed the time on my computer yesterday. This moring, I started my computer and I noticed that the time changed back to the old summer time. I set up the group policy to sync it to the Time Server on Windows Server 2003 and other client computers are synchronizing fine. I don't know how to fix the computer's summer time has once changed to the old setting.
Thank you for your help in advance.