How to download ISO file of Windows 10 21H1, May 2021 Update

You can download the ISO file to perform an in-place upgrade or clean installation of Windows 10 21H1 (May 2021 Update).

Windows 10 21H1 ISO early download
Windows 10 21H1 ISO early download

Windows 10 21H1 has been finalized as the May 2021 Update, and you can download the final ISO file right now to get early access to the first semi-annual update.

Microsoft has confirmed that version 21H1 will roll out sometime in May 2021 as a quick update that does not require full reinstallation, but if you cannot wait, the company is now making available the final version through its Windows Insider Preview Downloads page.

The ISO file is meant to allow commercial customers to test and validate the operating system before it becomes generally available. However, anyone can download it to start using the new version of Windows 10. The only caveat is that using the ISO file, you can only perform an in-place or clean installation that requires full reinstallation.

In this guide, you will learn the steps to download the ISO file to get early access to Windows 10 21H1.

Important: The May 2021 Update is officially available, which means you can now download the ISO file directly from the main download page.

To download the Windows 10 21H1 ISO file, use these steps:

  1. Open Windows Insider Preview Downloads page.

  2. Sign in with your Windows Insider Program credentials.

  3. Under the “Select edition” section, select the Windows 10 Insider Preview (Beta Channel) – Build 19043 option.

  4. Click the Confirm button.

  5. Select the product language.

  6. Click the Confirm button.

  7. Click the 64-bit Download button.

    Windows 10 21H1 ISO download (prerelease)
    Microsoft download page

Once you complete the steps, the final ISO for Windows 10 version 21H1 will download on the computer.

If you are running the 32-bit version of Windows, you need to use the 32-bit Download button.

After downloading the ISO file, you can use tools like Rufus to create a USB flash drive media. If you plan to perform an in-place upgrade, you can simply double-click the file to mount the ISO with File Explorer and proceed with the setup process.

Update May 18, 2021: The May 2021 Update is now officially ready for download on compatible devices. You can use these resources to get it now:

About the author

Mauro Huculak is a Windows expert and the Editor-in-Chief who started Pureinfotech in 2010 as an independent online publication. He is also been a Windows Central contributor for nearly a decade. Mauro has over 12 years of experience writing comprehensive guides and creating professional videos about Windows, software, and related technologies, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and