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October 13 Deadline: Office 2021, Windows 11 24H2 and Server 2012 Stop Getting Security Updates

Next Tuesday, Microsoft ends security updates for Office 2021, Windows 11 Home and Pro version 24H2, and the last paid extension for Windows Server 2012. Here's how to find affected PCs and what to do before the deadline.

  • microsoft
  • end-of-support
  • windows-11
  • office-2021
  • windows-server
  • patching
  • msp
  • smb
  • texas-it

Next Tuesday, October 13, 2026, is one of Microsoft's biggest retirement dates of the year. According to Microsoft's lifecycle pages, three products small businesses still use every day stop receiving security updates:

  • Office 2021 and Office LTSC 2021, including Word, Excel, Outlook, PowerPoint, Access, Publisher and Visio 2021.
  • Windows 11 Home and Pro, version 24H2. Windows 11 itself is still supported, but this particular version is not. Enterprise and Education editions of 24H2 stay supported until October 2027.
  • Windows Server 2012 and 2012 R2, which reach the end of their third and final year of paid Extended Security Updates.

Nothing shuts off on Wednesday morning. The software keeps running, which is exactly why it gets forgotten. What stops is the monthly flow of security fixes, so every new vulnerability found after October 13 stays open on those machines for good.

Why this matters for small businesses

Attackers watch these dates too. The PC at the front desk running Office 2021, the laptop that never moved off 24H2, or the old server in the closet that still runs the accounting app become easy targets once patches stop. Cyber insurance applications and compliance checklists such as HIPAA increasingly ask whether all systems are on supported software, so an unpatched machine can also become a paperwork problem after an incident.

Practical next steps (before Tuesday)

  1. Check every Windows PC's version. Press Windows + R, type winver, and press Enter. If it says Version 24H2 on Home or Pro, update to 25H2 or later through Settings, then Windows Update.
  2. Check every copy of Office. In Word or Outlook, go to File, then Account. If it says Office 2021 or Office LTSC 2021, plan a move to a supported version, such as Microsoft 365 Apps or Office 2024.
  3. Find any Windows Server 2012 or 2012 R2. There is no further extension coming. Migrate the workloads to a supported server or the cloud, or at minimum isolate that machine from the internet and the rest of the network until it's replaced.
  4. Write down what you find. A simple list of each device, its owner, its version and the fix date is what your insurer, auditor or MSP will ask for.
  5. Turn on automatic updates so the next version change happens on its own instead of waiting for a deadline.

For South Texas teams on-site: walk the office and run winver on every PC, including the shared ones at reception and in the warehouse. For remote-managed clients nationwide: ask your MSP for a report listing every device still on Office 2021, Windows 11 24H2 or Server 2012.

Nice2GeekYou is based in San Antonio, serving all of Texas, and our managed IT plans support remote clients across the U.S. with patch management, Windows and Office upgrades, server migrations and documented device inventories. Request a quote or see our monthly plans.

Sources: Microsoft Lifecycle, "Ending Support in 2026"; Microsoft Lifecycle, Windows 11 Home and Pro; Kocho SOC, "Cybersecurity Roundup October 2026" (Oct 7, 2026).