The Microsoft Windows Server rapture is coming

Inside Microsoft's secret design lab
Inside Microsoft's secret design lab

Here we go again.

Microsoft is phasing out old software that practically everyone is still using. And if companies don't upgrade, they'll be left behind as hack bait.

Nearly every business still uses Microsoft Windows Server 2003, but Microsoft (MSFT) is ending regular support for that software on July 14 this year. That means no more patches and upgrades.

Windows Server is the software running those back-end computers you never think about. You know, the ones processing everything from shopping websites to company email.

A bunch of them will be exposed this summer.

As of last month, 21% of all servers still run this aging software, according to tech supplier Softchoice.

But the situation is far more dire than that. Softchoice, which sells hardware and software to businesses, found that 97% of data centers still use Windows Server 2003 on a computer somewhere in the building.

The real issue here is that Windows Server 2003 is just about everywhere. The trouble is going to be finding every last one of these servers and upgrading them.

Once you find those computer, fixing the problem isn't easy. It takes about 200 days to upgrade, experts say. That means there's going to be a gap -- maybe months -- during which millions of computer servers will be potential hacking targets.

The "end of life support" for Microsoft Server 2003 is one of those problems that start tiny and could blow up over time.

It only takes one unpatched hole in a lone, long forgotten server to let a hacker break in and steal data. That's how a hospital lost 4.5 million patient records last year.

We all went through something similar last year, when Microsoft dropped support for Windows XP. That left 95% of ATMs exposed to cyberattacks.

The Windows XP rapture angered China so much, that the country blacklisted Windows 8 from all government computers and led China to build its own software to kill off Windows and Android. This Windows Server 2003 thing might flare up tensions again.

If a company decides to keep using Windows Server 2003, custom support from Microsoft will cost them $200,000 a year.

On the bright side, companies are ditching Microsoft Server 2003 for newer versions. But Softchoice found that they're hesitant to use the latest one. Only 4% of corporate computers use Microsoft Server 2012.

Microsoft Windows 10 in 90 seconds
Microsoft Windows 10 in 90 seconds

CNNMoney Sponsors