Support for Windows 10 Enterprise LTSB 2016, Windows 10 IoT Enterprise LTSB 2016 and Office 2021 ends on 13 October 2026. Windows Server 2016 follows on 12 January 2027. Microsoft extended consumer ESU by a year; no such extension applies on the enterprise side.
This week marks a significant threshold in Microsoft's support calendar. As of 13 October 2026, three enterprise products stop receiving security updates, and the countdown has begun for Windows Server 2016. From what we see in the field, many businesses are still running these systems unaware of the dates.
Products reaching end of support on 13 October
The following versions will receive no further security patches after 13 October 2026:
- Windows 10 Enterprise LTSB 2016
- Windows 10 IoT Enterprise LTSB 2016 — common in kiosks, POS terminals, production stations and measurement systems
- Office 2021 and Office LTSC 2021
Windows Server 2016 reaches end of support on 12 January 2027. For companies running file servers, Active Directory or ERP databases on this version, planning needs to start now.
An extra year for consumers, none for businesses
Microsoft quietly extended the Extended Security Updates (ESU) programme for consumer Windows 10 users to 12 October 2027. The previous end date was 13 October 2026.
That extension does not cover the enterprise LTSB and IoT editions. On the business side, ESU is a paid programme charged per device annually, and the fee compounds each year. ESU is therefore not a solution; it is buying time for a migration.
Why an unsupported system is a risk
End of support does not mean the device stops working. The risk is quieter: every vulnerability discovered after that date stays open permanently. Attackers know this, and because support calendars are public, legacy systems become priority targets.
There is a second dimension. Turkish Cybersecurity Law No. 7545 requires companies to take the necessary technical and administrative measures to secure their information systems. Knowingly running an unsupported operating system makes it easier to conclude that due measures were not taken should a data breach occur. Data security obligations under the data protection law point in the same direction.
Where to start
Start with an inventory. Which device runs which version, which licence expires when — without this, no plan is possible. In our experience, most businesses either lack this list entirely or hold an outdated one.
Once the inventory exists, the order of work is usually:
- Servers first. When an ERP or file server stops, the whole company stops; migration planning takes the longest here.
- Specialised devices second. POS terminals, kiosks and production stations usually depend on a specific software vendor; whether that vendor supports the new version must be confirmed in advance.
- Office workstations third. Where hardware allows, upgrading to Windows 11 is straightforward in most cases.
- Isolate what cannot be upgraded. Devices with insufficient hardware or incompatible software should be moved to a separate network segment with no internet access.
What we do at Kamer Bilişim
For clients under a maintenance agreement, we keep device and licence inventories continuously up to date and track end-of-support dates in advance. Thresholds like this one never come as a surprise; migrations are planned months ahead.
For businesses without an inventory, we carry out an on-site assessment: which operating system and version runs on each device, which will fall out of support, and which hardware can be upgraded. We report the findings with a priority order and estimated cost.
On the server side, we handle migration to Windows Server 2025, virtualisation and data transfer. We take a full backup before migration and keep a rollback plan ready.
To find out where your devices stand, get in touch with us.
Source: Microsoft Windows IT Pro Blog and Microsoft Lifecycle Calendar, October 2026.