Today, Microsoft is ending support for their Windows XP operating system, doing so an astounding thirteen years after XP was first released. For those who aren’t familiar with the history of desktop operating systems, back in the 1990’s, two to three years was the typical effective lifespan of a version of Windows. But for the last thirteen years, people have not only been using Windows XP regularly, it has remained one of the most used operating systems during much of that time. In fact, as Microsoft essentially puts Windows XP out to pasture, it still has 27% of the market, the number two operating system in use behind Windows 7 (at 48%).

Even more incredibly, there is really no legitimate reason to stop using Windows XP outside of the lack of support. Almost anything a modern PC user needs to do can still be done with XP. In fact, my main personal system at home, which we use for browsing, music, image management and gaming, was running Windows XP up until two weeks ago, when I upgraded the system to Windows 7.

Somewhat amusingly for me is the sense of déjà vu that I get from this end of the Windows XP era. Nine years ago, I wrote a similar piece extolling the longevity of Windows 98. In that column, I similarly expressed amazement over the longevity of Windows 98 as Microsoft was preparing to send that popular operating system out to pasture.

Of course, one key difference then as opposed to now was my amazement that Windows 98 had remained a popular and effective operating system for seven years, a longevity that Windows XP has almost doubled. If one was to carry out that trend to its next logical conclusion, then we could expect to see Windows 7 (or maybe 8.1) have an effective lifespan of over twenty years.

But I wouldn’t bet money on that.

That’s because the technology trends that have fueled Window XP’s longevity are not actually positive for desktop operating systems. Back in that old 2005 piece on Windows 98, I attributed its longevity to both the quality of 98 and to the overall slowdown in PC technology improvements. In the 90’s, a five year old PC was ancient. Today, there is nothing a computer built five years ago can’t run well.

To a large part this is because PC’s, while still useful, especially in business, are the technology devices of yesterday. There’s a whole segment of people today who use a tablet or smartphone as their main computing device and don’t own any form of PC or laptop.

When Windows XP debuted in 2001, the Blackberry was still just a pager, most cell phones were still just phones and the iPhone was still six years away. And during the last thirteen years, while desktop operating systems have barely evolved (evident in that nearly 30% of people still use a thirteen year old operating system), smartphones have basically gone from dumb cell phones to handheld computing platforms with more power than the personal computers of 2001.

While Windows 7 or 8 or whatever the next one is might have a long and useful lifespan, the time of the desktop being preeminent in computing has already passed. Thirteen years from now, who knows what we’ll be using. It could be glasses or contact lenses or computing devices that tap right into our head.

But one thing for sure is that it won’t be anything like a typical personal desktop computer of the last thirteen years.  Windows XP was the king of the last great desktop computing era. And the king is dead.