Windows XP. like all recent Win versions, allows you to display a clock in the System Tray at the lower right. (It's turned on by default, but someone might have turned it off, and would have to go to Control Panel and put it back.)

In WinXP only, if you double click it, a window opens that lets you make gross adjustments to date and time; but there should also be a tab there labelled "Internet Time." At that tab, you can click to put a check in the space for "automatically synchronize with internet time" and you can choose which "standards site" you want to synch to. Usually there are at least two choices, one of which is "Windows Time" (time.windows.com) and the other an NIST site (time.nist.gov).

This "synch" feature appears to be unique to WinXP, as a quick look at "her" Win2K doesn't find it.

Microsoft Using TIMESERV to Set and Synchronize Time (Article 232255) gives info on an NT utility that should be available in Win2K, although some versions and OEM packages omit it.

The article does give you the phone number of the Naval Observatory, which you might need with other programs:

For the US Naval Observatory, the values 'type=USNO' and 'Phonenumber=+1 202 762 1594'

"TIMESERV" is the standard NT utility, and an alternative is mentioned:

Some non-Windows NT clients unable to run Timeserv.exe may have a time synchronization command such as NET TIME \\servername /set /y

You're probably looking for an "aftermarket" program, and I'm sorry - I don't have one handy. Someone will come ...

John