- Double-click the clock in the system notification area (also known as the system tray).
- Click the "Internet Time" tab in the Date & Time Properties dialog box.
- Check "Automatically synchronize with an Internet time server," if it is not already checked.
- Choose a server from the drop-down list, or type one that you know yourself.
- Click Update Now to test the setting.
- If it worked, good. Your clock will synchronize once a week automatically when connected to the Internet. If not, try a different server.
This should work with all NTP time servers; I've tried a few, and settled on one that's on my LAN for maximum speed. The default server is "time.microsoft.com." It is worth noting that Microsoft has set this to enabled by default as they mandate product activation within the first 30 days after you boot Windows XP.