Last August Congress passed the Energy Policy Act, which makes daylight saving time (DST) start three weeks earlier and end one week later. The law goes into effect this year, which means we will all “spring forward” our clocks at 2:00 A.M. this Sunday (March 11, 2007).
Normally, with Microsoft Windows you don't have to manually change the time for DST. The operating system does it for you. However, the operating systems (except for Vista) aren't aware of the Energy Policy Act. You will need to install updates to make the change.
Here are the links for instructions on downloading and applying the updates.
Unfortunately, there is not a patch for Windows 2000 - you will need to update the computers manually.