Windows XP was officially discontinued by Microsoft on April 8, 2014, and despite the many warnings that the company has issued in the last 18 months, there still are plenty of users, companies, and organizations that keep running the same OS version.

The United Kingdom Royal Navy, for example, is running a Windows XP-based operating system on its submarines carrying war missiles, but officials claim that, despite the lack of patches, everything is 100 percent secure.

The Guardian has recently published an in-depth look at the company’s Trident nuclear submarines program, and among the details they have revealed, there’s also the name of the operating system powering the Vanguard series of submarines that are currently in use.

Windows for Submarines

A Windows XP-based operating system called “Windows for Submarines” is said to be powering these submarines because “it was cheaper than the alternatives,” although the same article acknowledges that everyone involved in this actually admitted that there are indeed some security risks associated with using an unsupported platform.

Basically, the biggest threat is experienced when submarines are called to ports to get software updates, as unpatched vulnerabilities in the operating system could be used by cybercriminals to break into their systems.

The Ministry of Defense isn’t worried that hackers could exploit vulnerabilities found in the unpatched operating system, and in a statement, officials explain they pay particular attention to keeping submarines protected against this kind of threats.

“Submarines operating in isolation by design, and this contributes to their cyber resilience. We take our responsibility to maintain a credible nuclear deterrent extremely seriously and continually assess the capability of our submarines to ensure their operational effectiveness, including against threats from cyber and unmanned vehicles,” they claim.

Right now, there are less than 10 percent of desktop computers across the world still running Windows XP, but figures are expected to decline even more as people continue to move to newer platforms, such as Windows 7, 8.1, or 10.