Windows 10 21H1 download

Windows 10 build 19043.964 release for version 21H1

The Windows 10 May 2021 Update (version 21H1) gets the update KB5001391 to fix one specific issue.

  • Windows 10 May 2021 Update receives the update KB5001391 (prerelease).
  • The update increases the version number of Windows 10 to build 19043.964.
  • This release only fixes a Blue Screen error and applies the build 19043.962 fixes.

As part of the May 2021 Update (version 21H1) development, Microsoft is now making available Windows 10 build 19043.964 for devices enrolled in the Beta and Release Preview channels of the Windows Insider Program.

The build 19043.964 is a small update rolling out as KB5001391 that only includes a fix for an “0xC2 (BAD_POOL_CALLER)” error that has been causing Blue Screen of Death (BSoD) when using “IOCTL_SCSI_PASS_THROUGH_DIRECT.”

If you missed the last update, this release also includes everything that the company fixed and improved with the update KB5001391 (build 19043.962).

Install Windows 10 21H1

If the device running version 20H2 is not enrolled in the Windows Insider Program, you first need to enroll it in the Beta or Releases Preview Channel before you can download the update. You can do this by going to Settings > Update & Security > Windows Insider Program and clicking the Get started button. 

In the wizard, click the Link an account option, select your Microsoft account, and click the Continue button. Under the “Pick your Insider settings” section, select the Beta Channel option (or Release Preview Channel), and click the Confirm button. Confirm the terms and conditions, restart the device, and then use the following steps to upgrade.

Then you can install Windows 10 21H1 going to Settings > Update & Security > Windows Update, click the Check for updates button, and then under the “Feature update to Windows 10, version 21H1” section, click the Download and install option.

About the author

Mauro Huculak is a Windows How-To Expert who started Pureinfotech in 2010 as an independent online publication. He has also been a Windows Central contributor for nearly a decade. Mauro has over 14 years of experience writing comprehensive guides and creating professional videos about Windows and software, 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 Email him at [email protected].