A Secure Boot certificate refresh is rolling out across supported Windows devices through Windows Update. In June 2026, the Secure Boot certificates that have shipped inside Windows since 2011 begin to expire, and Microsoft is replacing them with new 2023-dated certificates.

The good news: If you keep your PC updated, you probably won’t need to do anything. The bad news: Some older devices may not transition cleanly. Your PC won’t suddenly stop working, but over time it could miss important boot-level security protections without you realizing it.

Here’s what’s going on, why it matters, and how to check that your machine is on the right side of the deadline.

What is Secure Boot, and what’s expiring?

Secure Boot is a UEFI firmware feature built into virtually every PC sold since around 2012. It runs before Windows even starts loading, and its job is to verify that the boot loader and early boot components have been signed by a trusted party. If something tries to insert itself into the boot chain that isn’t on the trust list—a bootkit, for example—Secure Boot refuses to let it run.