Windows 10 ESU Activation (2026) — Y1/Y2/Y3 TSforge Guide

What is ESU and who needs it

ESU keeps Windows 10 secure for three more years after end-of-support. It is essential for any device that cannot upgrade to Windows 11 (older CPU, no TPM 2.0, missing Secure Boot, ARM32, embedded scenario). Each year of coverage is a separate paid license from Microsoft for enterprises — community-managed activation is available via TSforge.

Supported editions

Microsoft restricts ESU to selected SKUs.

• Windows 10 Pro
• Windows 10 Pro for Workstations
• Windows 10 Enterprise
• Windows 10 Education
• Windows 10 IoT Enterprise
• Windows 10 LTSC 2019 / 2021
• NOT supported: Home edition — upgrade to Pro first

Step-by-step activation

The base Windows 10 install must already be activated (HWID or KMS38) before installing the ESU key.

• Open KMSAuto.software_AIO.cmd as administrator
• Select ESU Activation from the menu
• Pick Year 1 (Oct 2025–Oct 2026), Y2, or Y3
• Wait for 'ESU successfully activated'
• Run Windows Update — KB-based ESU patches will now download

Verification

Open elevated CMD and run slmgr /dlv. Look for 'Windows(R) 10, ServerESU edition' in the description and a far-future expiry date. Reboot and check Windows Update — if ESU patches appear, you are done.

Yearly renewal

ESU keys are tied to a 12-month window. When Year 1 expires in October 2026, simply re-run KMSAuto.software and pick Year 2. No reinstall, no data loss.

Windows 10 ESU System Requirements & Compatibility (2026)

Windows 10 ESU is engineered for the modern Microsoft activation stack. The tool runs on Windows 7 SP1, Windows 8.1, Windows 10 (all builds from 1507 to 22H2) and every Windows 11 release including 23H2 and 24H2. Both x64 and ARM64 hardware are supported, and the activator also recognises Server SKUs such as Server 2016, 2019 and 2022. On the Office side, Click-to-Run installations of Office 2013, 2016, 2019, 2021, 2024 and Microsoft 365 are detected automatically — including LTSC channels. You do not need to uninstall a previous KMS client or remove an existing product key: the script reads the current edition through slmgr and routes it to the correct activation method (HWID for Windows, Ohook for Office).

• Windows 7 SP1 / 8.1 / 10 / 11 — all editions (Home, Pro, Education, Enterprise, IoT, LTSC)
• Windows Server 2008 R2 through Server 2025
• Office 2010, 2013, 2016, 2019, 2021, 2024 and Microsoft 365 Apps
• Architectures: x86, x64, ARM64
• .NET Framework 4.6+ (preinstalled on Windows 8.1 and later)

Windows 10 ESU Troubleshooting: Common Errors & Fast Fixes

Most Windows 10 ESU failures fall into three buckets: antivirus interference, missing administrator rights, or a corrupted Software Protection Service. If you see error 0xC004F074 the KMS host could not be contacted — disable Defender real-time scanning for two minutes, then re-run the activator. Error 0xC004C003 means the product key is blocked by Microsoft; switch to the HWID method, which bypasses key validation entirely by binding the licence to your motherboard's hardware ID. Error 0x80070005 (Access Denied) is always a UAC issue — right-click the executable and select "Run as administrator". If activation succeeds but reverts after reboot, open services.msc, set "Software Protection" to Automatic, and restart sppsvc.exe. For Office, run the Office Click-to-Run repair from Settings → Apps → Microsoft 365 → Modify → Quick Repair before retrying Ohook.

• 0xC004F074 — pause antivirus, re-run as administrator
• 0xC004C003 — switch to HWID (no key required)
• 0x80070005 — UAC denied, use "Run as administrator"
• Activation reverts on reboot — set "Software Protection" service to Automatic
• Office not detected — run Quick Repair, then re-run Ohook