It was big news when Microsoft announced it was working on a version of Windows that would run on tablets with ARM-based processors… but by the time Windows RT actually launched it was a lot less exciting. Devices like the Microsoft Surface and Surface 2 couldn’t run desktop Windows apps and weren’t significantly cheaper than Intel Atom-powered tablets running the full version of Windows, and they didn’t even get better battery life.
So it’s not particularly surprising that Microsoft has largely abandoned Windows RT. Devices like the Surface 2 can’t be upgraded to run Windows 10.
But Microsoft is continuing to push security updates to Windows RT… and if you happen to have one of the handful of Windows RT tablets that hit the market a few years ago the latest update has a surprise implication: it patches a Windows Secure Boot vulnerability that could have allowed you to replace Windows RT with another operating system.