Found this nice little tool for NTP synchronization. I like that it can be easily installed/uninstalled as a Windows service.
NetTime is a simple time synchronization client for Windows 95/98/NT/2000/Vista/7. Its main claim to fame is that it is small, simple and unobtrusive. And, of course, it’s free software.
You can download NetTime from http://www.timesynctool.com/