Windows XP has a cool feature that will automatically synchronize your system time for you.  First of all, you’ll need an Internet connection to make this work, I’m assuming you have one.

1. Double Click on the Time in the System Tray
2. The Date and Time Properties Window will Launch. Click on the Internet Time tab
   
3. Put a check mark in the box beside Automatically Synchronize With An Internet Time Server
4. Select the Server that you want to synchronize with. The default is time.windows.com
5. Click the Update Now button
6. Click Apply / OK

That’s all there is to it. Enjoy!