It was June 2021, and the tech world was basically convinced Microsoft was done with new versions of Windows. We’d been told for years that Windows 10 was "the last version of Windows." Then, a leaked build hit the internet, and suddenly everyone was staring at a centered taskbar and rounded corners.
Honestly, the timeline of when was windows 11 release is a bit of a mess if you don't look at the specific dates for announcements versus actual hardware shipping. It wasn't just a single "on" switch. It was a rolling, phased, and—for some people with older PCs—fairly frustrating rollout.
The Big Reveal and the Leaks
The official journey started on June 24, 2021. That was the day Panos Panay and the Microsoft team held a virtual event to unveil the OS. But the cat was already out of the bag. About a week earlier, on June 15, a nearly complete version of the software leaked onto various forums. People were already installing it on test machines before Microsoft could even finish the PowerPoint slides for the presentation.
During that June event, they didn't give a specific day for the launch. They just said "Holiday 2021."
The Official Launch Date
If you’re looking for the exact calendar date, Windows 11 was officially released on October 5, 2021.
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This was the "General Availability" (GA) date. If you went to a store like Best Buy that morning, you could buy a new laptop with Windows 11 pre-installed. For everyone else already on Windows 10, the "Update" button started appearing in settings, but only for a small group of users.
The Phased Rollout Schedule
Microsoft didn't just dump the update on every PC at once. They used a "phased and measured" approach. Basically, they used AI models to see which computers were the most compatible and least likely to crash, then they gave them the update first.
- October 5, 2021: New devices and "eligible" high-end PCs got the first wave.
- Late 2021 to Early 2022: The rollout expanded to more mid-range hardware.
- May 17, 2022: Microsoft finally announced that Windows 11 was "ready for broad deployment," meaning anyone with a compatible PC could finally go get it.
Why the Release Was Controversial
You've probably heard about the TPM 2.0 drama. While the release date was October 5, millions of people found out they couldn't actually install it. Microsoft set some pretty strict hardware requirements:
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- A compatible 64-bit processor (Intel 8th Gen or newer / AMD Ryzen 2000 or newer).
- 4GB of RAM.
- 64GB of storage.
- TPM 2.0 (Trusted Platform Module).
That last one was the kicker. Even if you had a powerful PC from 2017, if it didn't have that specific security chip active, the Windows 11 release might as well have been on Mars. It wouldn't show up for you. This created a weird situation where "release day" only applied to about 50% of the active PC market.
The Major Update Versions (2021–2026)
Since that original release, Windows 11 has basically evolved every year. We don't just talk about the 2021 launch anymore; we talk about the "versions."
The original version was 21H2 (Sun Valley). Since then, we've had:
- Version 22H2: Released September 20, 2022. This brought back some missing taskbar features and improved Snap Layouts.
- Version 23H2: Released October 31, 2023. This was the "Copilot" update that started shoving AI into the sidebar.
- Version 24H2: Released October 1, 2024. A massive under-the-hood rewrite, especially for ARM-based laptops like the Surface Pro 11.
- Version 25H2: The most recent major update, which hit systems around September 30, 2025.
Each of these "releases" felt like a mini-launch because they often changed how the UI worked or added system-level features that weren't there in the 2021 original.
What Most People Get Wrong
People often think Windows 11 was just a "skin" for Windows 10. While it started that way in the leaked June 2021 build, the actual October release changed the kernel's scheduler. It was specifically optimized for Intel’s "Thread Director" technology found in their hybrid CPUs. If you were using a 12th Gen Intel chip or newer, the Windows 11 release was actually a performance necessity, not just a visual choice.
Is Windows 10 Still Supported?
This is the big question now that we're well past the initial when was windows 11 release window. Microsoft has set a firm "End of Life" date for Windows 10: October 14, 2025.
We are currently in the post-support era for many versions of Windows 10. If you haven't moved to Windows 11 by now, you’re basically running on borrowed time unless you’re paying for the Extended Security Updates (ESU) program.
Actionable Steps for 2026
If you're still looking back at the Windows 11 release history because you're hesitant to upgrade, here is what you need to do:
- Check your TPM status: Hit the Windows Key + R, type
tpm.msc, and see if it's "Ready for use." - Verify your version: If you’re already on 11, go to Settings > System > About. If you aren't on at least 24H2, you're missing out on significant security patches and the new "Sudo for Windows" features.
- Hardware Assessment: If your PC was made before 2018, it’s officially time to consider new hardware. The 2021 release was the warning shot; the 2025 Windows 10 retirement was the deadline.
The release of Windows 11 wasn't just a date on a calendar; it was the start of Microsoft's shift toward AI-integrated operating systems. Whether you like the centered Start menu or not, the 2021 launch changed the trajectory of the PC forever.