Back in the late 2000s, computer firmware was moving from legacy BIOS to UEFI Unified Extensible Firmware Interface (UEFI). Alongside it came Secure Boot. This Microsoft-supported security mechanism was designed to stop bootkits and firmware‑level malware that traditional operating system security couldn't detect in its tracks. Secure Boot was messy, but it did the job. For people trying to install and run Linux on Windows PCs, this setup was a real pain in the rump. Here we are, 14 years after Secure Boot first appeared on Windows 8 PCs, and it once again has the potential to give Linux users a real headache.

Once again, some Linux lovers are in a panic that "Microsoft is locking Linux out!" That's not what's going on. As Microsoft pointed out, "Secure Boot certificates have always had expiration dates." Yes, yes, they have. Besides, as Ed Bott recently observed, while it's not nearly as annoying for Windows users, some people may still have trouble with expiring Secure Boot certificates.

The good news is that this concern is not a doomsday event for Linux. Your existing systems aren't going to wake up one morning and refuse to boot just because a date rolled over. But it is a moment of truth about how the Linux world has handled Secure Boot for more than a decade, and an opportunity for users to take more control, rather than quietly hoping that Microsoft and OEMs keep the lights on forever.

Also: I tested the best MacOS alternative on Linux again - and it even mimics Liquid Glass now

Let's walk through what's actually happening, why Linux is involved, and what you should be doing before 2026 and beyond.

To understand why, you have to go back to 2011 to 2012, when UEFI Secure Boot first landed on mass‑market PCs. The design goal sounded reasonable: stop untrusted code from running before the operating system by having firmware verify signatures of bootloaders, kernels, and option ROMs.