The Deadline You Missed
Windows 10 support ended October 14, 2025—eight months ago.
If you’re still running Windows 10 (and statistically, there’s a 50% chance you are), you’re not alone. But you are vulnerable.
No more security patches. No more bug fixes. Every day you run Windows 10, your systems become easier targets for attackers exploiting unpatched vulnerabilities.
Here’s why businesses delayed, what the risks are now, what Extended Security Updates (ESU) actually cost, and your realistic migration path to Windows 11 in mid-2026.
Why Half of Businesses Are Still on Windows 10 (8 Months After EOL)
The hard truth: Many businesses missed the deadline. You’re not alone.
Common reasons for delay:
- “We didn’t realize the deadline was October 2025” — not enough advance warning or communication
- “Our PCs don’t meet Windows 11 hardware requirements” — TPM 2.0 and CPU generation requirements blocked migration
- “We have legacy software that doesn’t work on Windows 11” — critical business applications not compatible yet
- “We were too busy with other projects to prioritize this” — IT backlog, staffing constraints, competing priorities
- “IT budget was allocated elsewhere” — no funds for hardware refresh or migration project
- “Windows 10 still works fine… why rush?” — no obvious immediate problem
The problem: Windows 10 *does* still work. It boots, runs applications, and doesn’t display scary error messages warning you of danger.
But under the hood, unpatched security vulnerabilities are piling up month by month.
What “End of Support” Actually Means (No More Security Patches)
What Microsoft Stopped Providing on October 14, 2025
- Security updates — no patches for newly discovered vulnerabilities
- Bug fixes — problems and errors aren’t getting fixed
- Technical support — Microsoft won’t help troubleshoot Windows 10 issues
- Feature updates — no new capabilities, improvements, or enhancements
What Still Works
- Windows 10 itself continues to function normally
- Applications keep running
- Hardware keeps working
- No forced shutdown or artificial degradation
- No warning messages or popup reminders
The Invisible Danger
- New security vulnerabilities discovered after October 2025 remain unpatched permanently
- Attackers actively target unsupported Windows versions (they know you can’t patch vulnerabilities)
- Compliance frameworks require supported software (HIPAA, SOC 2, PCI-DSS, cyber insurance policies)
- You’re one zero-day exploit away from a ransomware incident or data breach
Windows 10 feels fine today. But every month you stay on it, the risk grows.
Extended Security Updates (ESU): The Expensive Band-Aid
What ESU Provides
- Critical security updates only (not bug fixes, not feature updates)
- Available through October 2026 initially, can be extended through October 2028
- Sold per-device annually through Microsoft Volume Licensing
- Covers Windows 10 Enterprise, Pro, and Education editions
What ESU Costs (Per Device, Per Year)
- Year 1 (Oct 2025 – Oct 2026): $61 per device
- Year 2 (Oct 2026 – Oct 2027): $122 per device (doubles)
- Year 3 (Oct 2027 – Oct 2028): $244 per device (doubles again)
Real Cost for a 50-Device Business
- Year 1: $3,050
- Year 2: $6,100
- Year 3: $12,200
- 3-year total: $21,350 for temporary security patches that end in 2028 regardless
When ESU Makes Sense
- You have critical legacy software that absolutely cannot run on Windows 11 (and vendor has no migration path)
- Hardware refresh is planned and budgeted but not until fiscal year 2027
- You need 6-12 more months to complete a migration project already underway
- Compliance requires security updates and immediate migration isn’t feasible
When ESU Is a Waste of Money
- You’re using ESU as indefinite procrastination (it ends in October 2028 regardless—you’re just delaying)
- Hardware is already capable of Windows 11—you just haven’t prioritized migration yet
- You’d spend less money migrating now than paying ESU for 2-3 years
- You have no concrete plan to migrate before ESU ends in 2028
ESU is a bridge, not a destination. If you buy ESU Year 1, have a concrete plan to migrate before Year 2 doubles the cost.
The Windows 11 Hardware Reality Check
Minimum Requirements
- 64-bit processor, dual-core, 1GHz or faster
- 4GB RAM minimum (8GB+ strongly recommended for real-world business use)
- 64GB storage minimum (128GB+ recommended)
- TPM 2.0 (Trusted Platform Module security chip)
- UEFI firmware with Secure Boot capability
- DirectX 12 compatible graphics with WDDM 2.0 driver
The Dealbreaker for Many Businesses: TPM 2.0
TPM 2.0 is a security chip built into the motherboard. Most PCs manufactured before 2018-2019 don’t have TPM 2.0, or have TPM 1.2 which doesn’t meet Windows 11 requirements.
Which PCs typically support Windows 11:
- 8th generation Intel Core processors (2018+) or AMD Ryzen 2000 series (2018+) and newer
- Most business PCs purchased in 2019 or later
- PCs less than 5-6 years old from major manufacturers (Dell, HP, Lenovo)
Which PCs typically don’t support Windows 11:
- 7th generation Intel Core or older (pre-2018)
- 1st generation AMD Ryzen or older
- Most PCs from 2017 or earlier
- PCs over 6-7 years old
The hard truth: If your PCs are from 2017 or earlier, you’re almost certainly buying new hardware. There’s no easy workaround for missing TPM 2.0 that maintains security and support.
Microsoft offers workarounds to bypass TPM checks, but those PCs won’t receive updates reliably and may stop working with future Windows 11 releases.
Your Migration Path: Three Realistic Options
Option 1: Migrate to Windows 11 Now (Hardware Already Supports It)
Best for: PCs from 2019 or later that meet Windows 11 requirements
Migration steps:
- Audit your hardware — use Microsoft’s PC Health Check tool on each device to verify compatibility
- Test application compatibility — pilot test your critical business software, industry-specific apps, printers, scanners
- Back up everything — full system images or cloud backup before touching anything
- Run pilot migration — migrate 5-10 users first representing different roles, validate for 2 weeks, document and fix issues
- Roll out in phases — migrate remaining users over 2-4 weeks in manageable groups, not all at once
- Provide user training — Windows 11 UI is different (new Start menu, Settings app changes, right-click context menus)
Timeline: 1-3 months depending on business size and complexity
Cost: Minimal (mostly internal labor time, no ESU fees, no hardware purchases needed)
This is your best option if your hardware supports Windows 11. Don’t delay and pay ESU unnecessarily.
Option 2: Replace Aging Hardware + Migrate to Windows 11
Best for: PCs from 2018 or earlier that don’t meet Windows 11 hardware requirements
Migration steps:
- Assess which PCs need replacement — run PC Health Check tool, identify PCs without TPM 2.0 or old CPUs
- Budget hardware refresh — plan for $800-1,500 per business-grade PC depending on specs and vendor
- Order new PCs with Windows 11 pre-installed — most business PCs ship with Win11 Pro now
- Migrate user data — OneDrive sync (if using M365), manual file migration, or automated migration tools
- Deploy new PCs in phases — not everyone at once; reduce disruption and support burden
- Properly dispose of old hardware — data wiping and responsible e-waste recycling
Timeline: 2-4 months (hardware procurement lead times + phased deployment)
Cost:
- Hardware: $800-1,500 per PC (business-grade laptops/desktops)
- Migration labor: $5,000-10,000 depending on complexity and whether you use internal IT or MSP
For 50-device business: $40,000-75,000 in hardware + $5,000-10,000 in migration labor
This is expensive but unavoidable if hardware doesn’t support Windows 11. You need new PCs eventually anyway—better to do it now on your timeline than in a crisis.
Option 3: Buy ESU Year 1 as Bridge, Then Migrate Before Year 2
Best for: Businesses that genuinely need 6-12 months to plan, budget, and execute migration but can’t stay on unsupported Windows 10
Steps:
- Purchase ESU Year 1 immediately — $61/device through Microsoft Volume Licensing or CSP partner
- Create concrete migration plan — not “someday,” but specific timeline, budget, responsibilities
- Secure budget approval — for hardware refresh (if needed) or migration project
- Begin migration project — testing, piloting, procurement happening in parallel with ESU coverage
- Complete migration before October 2026 — avoid ESU Year 2 doubling to $122/device
Timeline: 6-12 months (use ESU as bridge while executing planned migration)
Cost: ESU Year 1 ($61/device) + eventual migration costs (hardware and/or labor)
Critical: Don’t let ESU become indefinite procrastination. Use it as a 6-12 month bridge to complete a migration you’re actively executing, not as a way to avoid dealing with the problem.
If you don’t have a concrete plan with timeline and budget when you buy ESU Year 1, you’re wasting money.
Application Compatibility: The Hidden Migration Blocker
Most business applications work fine on Windows 11. But some don’t, and those “some” might be critical to your business.
Applications That Often Have Issues
- Industry-specific software — medical practice management, manufacturing control systems, legal case management, specialized vertical apps
- Custom in-house applications — tools developed years ago for Windows 7 or 10 specifically
- Older hardware drivers — specialty printers, label printers, barcode scanners, production equipment
- Legacy accounting or ERP systems — older versions of QuickBooks, Sage, industry-specific platforms
Before Migrating, Test These Critical Apps
- Line-of-business software — your industry-specific apps, CRM, ERP, practice management systems
- Specialized hardware — label printers, barcode scanners, check printers, specialty medical/industrial devices
- Custom/proprietary tools — internally developed applications, Excel macros, Access databases, scripts
- Security and compliance tools — VPN clients, authentication tokens, compliance software
If Critical Software Doesn’t Work on Windows 11
- Contact vendor for Windows 11-compatible version or migration timeline
- Consider virtualization — run Windows 10 in a VM on Windows 11 host for that one incompatible application
- Evaluate alternatives — cloud/SaaS replacements that aren’t OS-dependent
- Last resort: ESU for affected PCs while you find long-term solution or plan vendor migration
Application compatibility is why you pilot test before full migration. Find these issues early with 5-10 pilot users, not after migrating your entire organization.
The Security Risk of Staying on Windows 10 (Real Consequences)
How Attackers Exploit Unsupported Windows
- Monitor Microsoft’s monthly Patch Tuesday to see what vulnerabilities got patched in Windows 11
- Reverse-engineer those patches to understand the underlying vulnerability
- Exploit those same vulnerabilities in unpatched Windows 10 systems (knowing you can’t patch them)
Timeline of Increasing Risk
- October 2025 (EOL date): Low immediate risk, no new vulnerabilities yet
- January 2026: Moderate risk (3 months of unpatched vulnerabilities accumulating)
- June 2026 (now): High risk (8 months unpatched, multiple known exploits in the wild)
- October 2026: Very high risk (12 months unpatched, Windows 10 actively targeted)
- 2027-2028: Extreme risk (Windows 10 systems are low-hanging fruit for attackers)
Real Consequences
- Ransomware attacks exploiting unpatched Windows 10 vulnerabilities
- Data breaches through compromised Windows 10 endpoints
- Failed compliance audits — HIPAA, SOC 2, PCI-DSS all require supported operating systems
- Cyber insurance claims denied — “You were running unsupported OS when the breach occurred”
- Increased insurance premiums at renewal (insurers checking what OS you’re running)
- Client trust damage — “You let our data sit on unsupported systems?”
The risk isn’t theoretical. Windows 10 systems are being actively exploited right now.
The Migration Timeline (What’s Realistic in Mid-2026)
If you’re starting your Windows 10 migration in June 2026, here’s what to expect:
Fast Track (1-2 Months)
- Small business (under 25 users)
- Hardware already meets Windows 11 requirements
- No critical legacy application compatibility issues
- Can tolerate some disruption during migration
- Internal IT can handle migration or MSP available immediately
Standard Pace (2-4 Months)
- 25-100 users
- Most hardware compatible, some PCs need replacement
- Application compatibility testing required for several business-critical apps
- Phased rollout needed to minimize business disruption
- User training and change management important
Extended Timeline (4-6 Months)
- 100+ users
- Significant hardware refresh needed (many PCs don’t meet requirements)
- Complex application landscape with multiple legacy systems
- Extensive testing, piloting, and user training required
- Budget approval process, procurement lead times, phased deployment
What to Do Right Now (Action Steps)
This Week
- Run hardware assessment — download Microsoft PC Health Check tool, run on every PC, document results
- Identify which PCs can upgrade vs. need replacement — separate into buckets: compatible, marginal, incompatible
- List critical applications that need compatibility testing before migration
This Month
- Test Windows 11 with pilot group — 5-10 users with representative mix of hardware, software, and roles
- Get budget approval — for hardware refresh (if needed) or ESU Year 1 (if delaying) or migration project labor
- Create migration project plan — specific timeline with milestones, phases, responsibilities, user communication plan
Next 90 Days
- Execute phased migration — roll out in manageable groups, not all at once
- Provide user training and support — Windows 11 is different enough to need guidance
- Complete before ESU Year 2 (if using ESU) — avoid $122/device cost increase in October 2026
The ESU vs. Migration Cost Comparison
Scenario: 50 PCs, half need hardware replacement due to age/compatibility
Option A: Stay on Windows 10 with ESU for 3 Years
- ESU Year 1 (2025-2026): $3,050
- ESU Year 2 (2026-2027): $6,100
- ESU Year 3 (2027-2028): $12,200
- Total: $21,350 over 3 years
- Result: You’re still on Windows 10 in October 2028 when ESU ends, still need to migrate eventually
Option B: Migrate Now
- Replace 25 incompatible PCs: $25,000 (at $1,000 average per business PC)
- Migration labor (testing, deployment, training): $5,000
- Total: $30,000 one-time cost
- Result: You’re on supported, secure Windows 11 immediately with new hardware under warranty
The Math
Migration costs $8,650 more upfront than 3 years of ESU, but:
- You’re on a supported, secure OS immediately (no accumulating security risk)
- No ongoing annual ESU fees
- New hardware with 3-5 year warranty
- Better performance and reliability from new PCs
- You’ll need new PCs eventually anyway (hardware doesn’t last forever)
ESU only makes financial sense if: You genuinely need 6-12 months to complete a migration project already in progress, and buying ESU Year 1 lets you complete that migration properly instead of rushing.
Don’t use ESU as indefinite procrastination. It’s more expensive long-term and you still end up migrating eventually.
Common Mistakes to Avoid
1. Assuming Windows 10 Is “Fine” Because It Still Works
It boots and runs applications normally. But unpatched security vulnerabilities are accumulating every month. You’re vulnerable even if you don’t feel it yet.
2. Buying ESU Year 1 Without a Concrete Migration Plan
ESU is a bridge to give you time to migrate, not a permanent solution. If you buy ESU without a specific timeline and budget to migrate before Year 2, you’re wasting money.
3. Migrating Everyone at Once Without Pilot Testing
Pilot first with 5-10 users. Test critical applications. Find and fix issues. *Then* roll out organization-wide. Don’t discover your accounting software doesn’t work after migrating 50 users.
4. Ignoring Application Compatibility Until It’s Too Late
Test your critical business software on Windows 11 *before* you commit to migration. Finding out your industry-specific app doesn’t work after you’ve already started is expensive and disruptive.
5. Underestimating User Training and Change Management
Windows 11 UI is different enough from Windows 10 that users will have questions and frustrations. Plan for training, quick-reference guides, and extra IT support during the transition period.
The Bottom Line
Windows 10 support ended October 14, 2025. If you’re still running it in June 2026, you’re 8 months past the deadline and accumulating unpatched security vulnerabilities daily.
Your realistic options right now:
- Migrate to Windows 11 immediately (if hardware supports it) — best option, lowest cost, eliminate security risk now
- Replace aging PCs + migrate to Windows 11 (if hardware doesn’t support it) — expensive but unavoidable, you need new PCs eventually
- Buy ESU Year 1 as 6-12 month bridge (if you need time to plan/budget) — temporary only, must have concrete migration plan
Don’t do: Stay on unpatched Windows 10 indefinitely hoping the problem goes away. The security risk compounds every month, and compliance/insurance issues will catch up to you eventually.
If you haven’t started planning your Windows 10 migration yet, start this week. Every month you delay increases your security risk and makes the eventual migration more rushed, stressful, and expensive.
You’re late, but you’re not out of time yet. Act now.
Need Help Planning Your Windows 10 Migration?
Figuring out which PCs can upgrade vs. need replacement, how to test application compatibility without disrupting your business, and how to execute a phased migration without overwhelming your team—that’s where businesses get stuck.
At Castle Rock Sky, we help Denver metro businesses migrate from Windows 10 to Windows 11 without the headaches, panic, or business disruption.
We can:
- Assess your hardware — which PCs support Windows 11, which need replacement, realistic cost and timeline estimates
- Test application compatibility — identify compatibility issues before migration, find solutions for legacy software that doesn’t work
- Create migration project plan — phased rollout strategy, timeline with milestones, budget breakdown, user communication plan
- Execute the migration — pilot testing, full phased deployment, user training, post-migration support
- Handle ESU procurement (if you need a temporary bridge) and ensure you complete migration before Year 2 costs double
- Procure and deploy new hardware (if needed) — business-grade PCs with Windows 11, data migration, proper disposal of old equipment
Don’t let Windows 10 end-of-support turn into a security incident, compliance failure, or insurance claim denial. Start your migration now while you still have time to do it properly.
