Now let's look at the flip side: If you don't have a Y2K-compliant PC, or of you haven't applied the Y2K patches, then changing the date-display format is just rearranging the deck chairs on the Titanic: Changing the format does nothing to ensure that the date is correct in the first place.
In fact, simply using four-digit dates won't do you any good at all if the rest of your version of Windows, or the rest of your software or your PC itself has any of about five completely separate Y2K issues. This "set a four-digit date format and you'll be fine" approach is way too simplistic. It's totally misleading. It's wrong.
Fortunately, the real Y2K tests, and the real fixes, are ridiculously easy:
Start by getting correct Y2K patches for whatever version of Windows you use by going here: http://www.microsoft.com/y2k.
If you wish, go ahead and set your PC's date display to four digits. It does no harm.
But don't stop there: In about 5 minutes, and for free, you can check each of the various date-related subsystems in your PC and thus know, for sure and for real--regardless of what the chain e-mail letters are telling you--whether or not your PC or OS has a Y2K problem. And if there is a problem, chances are you can fix it easily and at low cost. It's all detailed here: "Tick, Tick, Tick....Are You Ready for 2000"
Okay, now what other Y2K scares can we debunk? <g> Or more seriously, what real Y2K issues do you face? Join in the discussion!