Microsoft has released today the Windows 10 Insider Preview Build 14926 for PC and Mobile, and the new bits come with a warning from the Windows Insider team about expiration dates for old preview builds. If your PC is currently running a "really old Insider build" (Microsoft didn't share more details, but we guess the company meant old Windows 10 Insider builds version 1511 or earlier), you will start seeing expiration notifications starting tomorrow, September 15th.
If you don't update your PC to the latest Insider build available on your Insider Ring before October 1st, your PC will then start rebooting every three hours and it will completely stop booting on October 15th. That's pretty radical but hey, updating your PC to the latest Insider build is a straightforward process: just go to Settings > Update & security > Windows Update and check for new updates.
Here's how Head of the Windows Insider program Dona Sarkar explained it today:
Just as we’ve always done with pre-release versions of Windows, Insider Preview builds have expiration dates. Starting tomorrow September 15th, PCs running really old Insider Preview builds will start to see build expiration notifications once a day. Then on October 1st, these PCs will start rebooting every 3 hours and then on October 15th – these PCs will stop booting all together. If your PC is running one of these old Insider Preview builds, please make sure you update to Build 14926 via Settings > Update & security > Windows Update. Build 14926 has an updated expiration date of May 1st, 2017. If your PC is running the Windows 10 Anniversary Update (Build 14393) in the Slow and Release Preview rings today – this does not apply to you and you will not be notified of your build expiring.
If you're on the Insider Fast Ring, we invite you to read our other posts detailing what's new in the new Windows 10 Redstone 2 build 14926. If you're still running an old Insider build, let us know why in the comments and tell us if you're going to update as soon as possible.