- 62 devices can move to Windows 11 with a free in-place upgrade — you only pay labour (£2,480).
- 38 devices genuinely need replacing (unsupported CPU or no TPM 2.0). A full 3 years of ESU costs £350/device (£50 → £150 → £350 cumulative — it doubles AND stacks), versus about £370 to refresh with a refurbished Windows 11 PC.
- A single year of ESU is a cheap, compliant bridge that buys time to phase the refresh into next budget — but do not carry it to Year 3, where the doubling makes it a false economy.
Don’t treat the fleet as one bucket
The single biggest costing mistake is assuming “end of support” means “buy everyone a new PC”. It doesn’t. Most Windows 10 fleets split three ways: machines that meet the Windows 11 bar and upgrade in place for free (you pay only labour); machines that fail the check but are fixable for free by enabling TPM/Secure Boot in the BIOS or converting the disk to GPT; and a genuinely stuck minority with an unsupported CPU or no TPM that really do need replacing. This calculator asks for each bucket separately, because only the last one carries hardware cost.
ESU is a bridge, not a destination
Extended Security Updates buy time — but Microsoft designed them to get more expensive fast: the price doubles every year and is cumulative (buy Year Two and you owe Year One too), so three years runs to about $427 per device. That routinely exceeds the cost of a refurbished Windows 11 PC, and at the end you still own an end-of-life machine. The honest recommendation is usually a short one-year bridge on the stuck devices while you phase in replacements — which is exactly what the tool works out and what the break-even year pins down.
Windows 10 ESU pricing & Windows 11 requirements
Commercial ESU is published by Microsoft in US dollars. GBP is always an indicative estimate you confirm via a reseller — never a firm price.
Commercial ESU per device (Microsoft Volume Licensing)
| ESU year | Coverage window | This year (USD) | Cumulative (USD) |
|---|---|---|---|
| Year 1 | Nov 2025 – Oct 2026 | $61 | $61 |
| Year 2 | Oct 2026 – Oct 2027 | $122 | $183 |
| Year 3 | Oct 2027 – Oct 2028 | $244 | $427 |
Price doubles each consecutive year, maximum three years, and is cumulative. Devices managed via Intune/Windows Autopatch get ~25% off Year One (~$46). Azure/AVD/Windows 365 seats: no additional cost.
Windows 11 hardware bar (what makes a PC eligible)
| Requirement | What it means (and whether it’s free to fix) |
|---|---|
| TPM | TPM 2.0 (often disabled in BIOS as fTPM/PTT — enabling it is free) |
| Boot | UEFI with Secure Boot capable (MBR→GPT conversion is free, no new hardware) |
| CPU | Supported 64-bit CPU — effectively Intel 8th Gen+ / AMD Ryzen 2000+ / Qualcomm |
| RAM | 4 GB or more |
| Storage | 64 GB or more |
| Graphics | DirectX 12 / WDDM 2.0 compatible |
Verified against: Microsoft Learn (2025-11-17) · Microsoft Learn (2026-04-22) · Microsoft Windows IT Pro blog (2025) · Microsoft (2026-06) · Microsoft Learn (2026) · Microsoft Learn (2026) · Microsoft Support (2026) · Microsoft Learn (2026) · NCSC/IASME (2026) · PCI SSC (2024).
Windows 10 end-of-life FAQs
When did Windows 10 reach end of life?
Windows 10 (version 22H2, all editions) reached end of support on 14 October 2025. From that date Microsoft no longer ships feature updates, security updates or technical support for it. The operating system keeps working, but every unpatched vulnerability discovered after that date stays open unless the device is covered by Extended Security Updates (ESU) — which deliver security fixes only, no new features or general support.
How much does Windows 10 ESU cost for businesses?
Commercial ESU is a per-device annual subscription through Microsoft Volume Licensing at $61 USD for Year One. The price DOUBLES every consecutive year for a maximum of three years — so $61, then $122, then $244 — and it is CUMULATIVE: if you start in Year Two you must also buy Year One, so the three-year cumulative cost is about $427/device. Devices managed with Intune or Windows Autopatch get roughly 25% off Year One. Microsoft publishes ESU in US dollars; the GBP figure a UK reseller quotes will differ, so this tool treats the £ price as an editable estimate.
Is upgrading from Windows 10 to Windows 11 free?
Yes — the in-place upgrade is free for genuine, licensed Windows 10 devices (on version 2004 or later with the September 2021 update, practically 22H2) that meet the Windows 11 hardware requirements. There is no announced end date for the free upgrade. Your only cost is the engineer/labour time to validate, upgrade and test each machine — which this calculator counts as a first-class input.
How do I know if a PC can run Windows 11?
A device needs TPM 2.0, UEFI with Secure Boot, a supported 64-bit CPU (effectively Intel 8th generation or newer, AMD Ryzen 2000 or newer), at least 4 GB RAM and 64 GB storage. Crucially, many machines that fail the check are fixable for free — TPM is often present but disabled in the BIOS (fTPM/PTT), Secure Boot may just need enabling, and a legacy-BIOS disk can be converted MBR→GPT. Only a genuinely unsupported CPU or an absent TPM forces a hardware replacement. Use Microsoft PC Health Check or Intune Endpoint Analytics to assess a fleet, and enter the fixable count separately in the tool.
Should we buy ESU or just replace the PCs?
For the devices that can upgrade in place, neither — just upgrade them (free bar labour). For the genuinely not-capable devices it is a trade-off, and because ESU doubles and is cumulative it is usually a short bridge, not a destination: three years of ESU (~$427/device) typically costs more than a refurbished Windows 11 PC, and you still own an end-of-life machine afterwards. The honest answer this calculator surfaces is often: upgrade the capable devices now, take at most a one-year ESU bridge on the stuck ones, and phase in refurbished (or new) replacements before the break-even year.
What are the compliance risks of staying on Windows 10?
Running an unsupported operating system in scope is an automatic Cyber Essentials failure unless the device is removed or segregated, and the standard also requires critical/high vulnerabilities to be patched within 14 days. PCI DSS requires vendor-supported software (requirement 6.3.3 sets a patch window; 12.3.4 requires a review and remediation plan for end-of-life technology). Many cyber-insurance policies limit or void cover for unsupported systems. ESU restores security-update eligibility, but the tool still flags the exposure and the hard end of commercial ESU around October 2028.
Do cloud PCs and Azure VMs need paid ESU?
No. Windows 10 running in Azure, Azure Virtual Desktop, Azure VMs, Azure Local, and Windows 365 Cloud PCs receive ESU at no additional cost, and physical endpoints connecting to a Windows 365 Cloud PC are also entitled. The calculator lets you enter those as "cloud/VDI seats" and excludes them from the ESU spend.
How accurate are these figures?
The ESU rules (Year-1 price, the doubling, the cumulative purchase, the three-year cap, the 25% managed discount) and the Windows 11 requirements are taken verbatim from Microsoft Learn and cross-checked in an adversarial fact-check pass (July 2026). The maths is deterministic and test-covered. What is NOT baked in as fact: the GBP ESU price (Microsoft publishes USD — we show an editable estimate), your device and labour costs (your own estimates), and any carbon figures (editable inputs). A Servnet specialist confirms firm UK pricing before you buy.
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