Microsoft announced that Windows 11 has surpassed one billion monthly active devices worldwide. The operating system reached the milestone in just over four years—faster than Windows 10 did after its 2015 launch, which took about five years to hit the same figure. The news underscores how the strict hardware requirements, enhanced security, and the looming end-of-support deadline for Windows 10 have combined to accelerate adoption.

The milestone by the numbers

Windows 11 launched on October 5, 2021, so hitting one billion devices in roughly four years and a few months represents a quicker uptake curve than its predecessor. Windows 10, released on July 29, 2015, crossed the billion-device threshold in March 2020—about four years and eight months later, but that OS faced a much larger install base to grow from and a free upgrade offer that blunted early momentum. Microsoft’s own tracking shows Windows 11 adoption accelerating over the past 18 months, driven by new PC sales and a spike in voluntary upgrades as the October 14, 2025 end-of-support date for Windows 10 approaches.

“Reaching one billion devices is a testament to how people are embracing the modern, secure, and AI-driven experiences Windows 11 delivers,” a Microsoft spokesperson said in a statement accompanying the announcement. The company did not break down the number by consumer versus commercial devices, but analysts estimate commercial deployments have lagged, with many organizations only now completing their migration from Windows 10.

What the billion-user figure means for you

If you’re still on Windows 10

The clock is ticking louder than ever. After October 14, 2025, Windows 10 Home and Pro will no longer receive free security updates, leaving your system vulnerable to new exploits. The billion-user milestone means the Windows ecosystem is now solidly centered on Windows 11—software developers, peripheral makers, and IT support will increasingly target the newer OS, potentially leaving Windows 10 users with fewer compatible apps and accessories over time.

If your PC meets the hardware requirements, upgrading now ensures you stay protected and enjoy features like tabbed File Explorer, live captions, and the Copilot AI assistant. If your hardware isn’t compatible, you’ll need to weigh the cost of a new PC against the risk of running an unsupported OS. (More on those options below.)

For business and IT administrators

A billion-strong install base makes Windows 11 the de facto standard for security and management tooling. Vendors of endpoint protection, device management, and compliance software are already optimizing for Windows 11’s advanced security features—such as hardware-enforced stack protection and virtualization-based security—that simply aren’t available on Windows 10. If your organization hasn’t finished migrating, the milestone is a prompt to accelerate. Delaying into 2026 means your fleet could be exposed on the day support ends, and you’ll compete for limited IT resources as the deadline hits.

For developers and power users

Windows 11 now has a critical mass that justifies building apps that lean on modern APIs. If you develop software, a billion users means the market for WinUI 3, Windows App SDK, and AI-infused experiences is large enough to prioritize. Power users can expect more third-party utilities to adopt the newer OS’s visual style and capabilities, while older tools that only test on Windows 10 may gradually fall behind.

How we got here: the rocky road to 1 billion

Windows 11’s journey was anything but smooth. At launch, the operating system drew sharp criticism for its stringent hardware requirements—TPM 2.0, Secure Boot, and an 8th-generation or newer Intel CPU (or Ryzen 2000 and newer). That instantly rendered millions of otherwise functional PCs ineligible, angering users and IT departments alike.

Adoption crawled for the first two years. By October 2023, Windows 11 held just over 23% of Windows market share, according to Statcounter, while Windows 10 still commanded over 71%. Several factors then turned the tide:

  • The Windows 10 end-of-support clock: Microsoft’s unwavering October 2025 deadline forced both consumers and enterprises to plan upgrades. By early 2024, every passing month made the deadline more tangible.
  • New hardware uptake: PC sales rebounded in 2024 as remote and hybrid work settled into a permanent pattern. New laptops and desktops shipped with Windows 11 by default, adding tens of millions of devices each quarter.
  • AI hype and Copilot+ PCs: In 2024, Microsoft unveiled Copilot+ PCs—devices with neural processing units (NPUs) capable of running AI tasks locally. The only way to get those features was on Windows 11, turning the OS into a gateway to the AI-powered future Microsoft has been heavily marketing.
  • Microsoft’s gentle nudges: Full-screen upgrade prompts, an improved PC Health Check app, and the ability to easily roll back within 10 days lowered the perceived risk for cautious users.

The result: by mid-2025, Windows 11’s share crossed 50%, and the billion-user mark came into view.

What to do now: a step-by-step upgrade guide

If you’re among the holdouts, here’s exactly how to get to Windows 11 without losing data or time.

1. Check your PC’s compatibility

Download and run Microsoft’s PC Health Check tool from the official website. It will instantly tell you if your device meets the minimum requirements. The non-negotiable items are:

  • TPM 2.0 (often can be enabled in your BIOS if it’s turned off)
  • Secure Boot capability
  • 64 GB or more storage
  • 4 GB of RAM (8 GB recommended)
  • A compatible 64-bit processor (Intel 8th gen or later, AMD Ryzen 2000 or later, or Qualcomm Snapdragon 850 or later)

If the tool says you’re good to go, proceed. If not, you’ll see exactly which component fails.

2. Back up your data

Before any major OS upgrade, create a full backup. Use Windows 10’s built-in “Backup and Restore (Windows 7)” tool or a third‑party imaging tool to save a system image to an external drive. Also, sync important files to OneDrive or another cloud service as a safety net.

3. Upgrade using Windows Update or the Installation Assistant

  • Open Settings > Update & Security > Windows Update and check for updates. If your device is ready, you’ll see “Upgrade to Windows 11 is ready for your PC.”
  • If the update isn’t offered yet, you can manually trigger it using the Windows 11 Installation Assistant, available on Microsoft’s download page. It works like a guided setup and preserves your apps and files.
  • For a truly clean start, you can create a USB installation drive using the Media Creation Tool, but that requires a custom install and repopulating your data afterward.

4. If your PC can’t run Windows 11

You have three choices:

  • Buy a new PC: That’s the path Microsoft recommends. New machines come with Windows 11, modern hardware, and often include NPUs for AI features.
  • Pay for Extended Security Updates (ESU): Microsoft will offer ESU for Windows 10 to individual consumers for the first time, expected to cost around $30 per year for the first year. Businesses can purchase ESU through volume licensing. This buys you a few more years of critical patches.
  • Switch to an alternative OS: Some users are installing Linux distributions like Ubuntu or Linux Mint on older hardware. Others are moving to ChromeOS Flex. Both can breathe new life into aging machines, but expect a learning curve and missing features like full Microsoft Office compatibility.

Outlook: What’s next for Windows 11 and beyond

Passing a billion users provides Microsoft with a sturdy base to push its next wave of features. The 24H2 update, rolling out now, brings more AI integration, including Windows Recall (a controversial searchable timeline of your activity) and improved Voice Clarity. Future updates are expected to deepen Copilot’s reach across the operating system.

The milestone also mutes any lingering questions about Windows 11’s viability after a slow start. With Windows 10 officially transitioning into its end-of-life phase, all eyes are on how quickly the remaining half a billion or so users move over—and whether Microsoft might finally loosen some of those hardware requirements to avoid a massive security gap. For now, the billion number is a clear signal: Windows 11 is the present and the future of the Windows ecosystem.