NetTime is a simple time synchronization client for Windows 95/98/NT/2000. Its main claim to fame is that it is small, simple and unobtrusive. And, of course, it's free software. Here are some screenshots (not quite the latest version, though).
Note that Windows XP and Windows 2000 include a full-featured NTP client out of the box, and it's a free download from Microsoft for Windows NT. There is longer any no good reason to use NetTime on Windows NT, 2000 or XP.
Also note that development stopped on the NetTime project years ago. Among other things, its built-in list of NTP servers is extremely outdated - please don't use it; refer to the official list (above) instead.
And you're on your own for bug fixes - the project is officially abandoned by me at this point. If you come up with interesting new code, by all means send it to me; I'm perfectly willing to do maintainer-type work. But for heaven's sake people - please stop sending me feature requests for things the Microsoft code already does. At least not without a good reason why NetTime should do it as well.