In the beginning of June, the U.S. Navy reportedly signed a $30.8 million contract with Microsoft to keep supporting PCs that run Windows XP at the Space and Naval Warfare Systems Command, according to PC World. The U.S. Navy will pay Microsoft $9.1 million a year until 2017.

Microsoft ended public support for Windows XP on April 8 2013, notifying users that continued use would leave their computers more vulnerable to malware and hacking.

Which is why a declassified Navy document obtained by PC World warned that without Microsoft's "continued support, vulnerabilities to these systems will be discovered, with no patches to protect the systems." The document further cautioned that the resulting "deterioration" would put Navy's computers in danger of being infiltrated by hackers.

In 2013, the Navy started transitioning out of Windows XP but wasn't fast enough. As of now the Navy still operates at least 100,000 PCs running Windows XP. And they aren't alone, 16.9 percent of PC owners were browsing the web with Windows XP in March, according to Net Applications.

Fortunately because of the contract, Microsoft will continue issuing security updates for Windows XP, Microsoft Office 2003, Windows Server 2003 and Exchange 2003 to the Navy.

"The Navy relies on a number of legacy applications and programs that are reliant on legacy Windows products, until those applications and programs are modernized or phased out, this continuity of services is required to maintain operational effectiveness." said Steven Davis, Fleet Liason Officer at the Office of Naval Intelligence.

Davis added that the Navy was making inroads in updating their PCs to more contemporary operating systems. Still, they clearly don't think they'll be finished until 2017. What the 100,000 Windows XP Navy computers control remains classified.