Three important Microsoft support deadlines all passed on the same day last week (13 October, US time), and they’re easy to miss:
- The first year of paid Extended Security Updates (ESU) for Windows 10 finished, and the price has now gone up.
- The last year of extended updates for Windows Server 2012 and 2012 R2 ran out.
- Office LTSC 2021 reached the end of its support life.
None of this came out of the blue. Microsoft published these dates years ago. But a year after Windows 10 officially reached end of support, we still find the odd PC, server or old copy of Office that falls into one of these groups. For our KARE clients, they show up in their health reports, so nothing slips through quietly.
Windows 10: year two of ESU costs double
Windows 10 support ended on 14 October 2025. Since then, the only way to keep a Windows 10 PC getting security patches has been Microsoft’s paid ESU programme. Microsoft’s own documentation says the ESU price doubles every year, for up to three years. So year two costs twice as much as year one.
There is one exception, and it’s in the cloud. Windows 10 running in Windows 365, Azure Virtual Desktop or an Azure virtual machine gets ESU at no extra charge. Microsoft also covers Windows 10 devices used to connect to Windows 365 Cloud PCs for up to three years while the subscription is active.
Also worth knowing: ESU only includes critical and important security fixes for Windows 10 version 22H2. No new features, no other bug fixes and no general technical support from Microsoft.
Windows Server 2012 and 2012 R2: no more updates, ever
Windows Server 2012 R2 left extended support back in October 2023. Businesses that needed more time could buy up to three years of ESU, and that third year ended on 13 October 2026. There’s no fourth year.
That means any 2012 or 2012 R2 server still running (often an old file server, or the one running a line-of-business app nobody wants to touch) will never get another security patch. And the timing isn’t great. October’s Patch Tuesday landed on the same day, with Qualys counting 1,414 vulnerabilities fixed across Microsoft products, 78 of them rated critical. One of them, a Windows Shell security feature bypass (CVE-2026-96951), was already being exploited, and CISA added it to its Known Exploited Vulnerabilities list.
Office LTSC 2021: still works, but no more fixes
Office LTSC 2021 is the “buy it once” version of Office some businesses chose instead of a Microsoft 365 subscription. Its support ended on 13 October 2026, with no extended phase after that. It will keep opening documents, but Microsoft won’t release any more security fixes for it. For most businesses, moving those users onto Microsoft 365 apps is the obvious next step.
Where to start
Start by finding out what you’ve actually got. A proper device and software inventory will show you which PCs are still on Windows 10 (and whether they can run Windows 11), which servers are on 2012 or 2012 R2, and where Office 2021 is still installed. From there you can decide what to upgrade, what to move to the cloud and what to retire.
Not sure what’s lurking in your environment? We’ll find it for you. Book a free health check, or call us on 0800 688 768.