Windows 10 update settings with purple background

Windows 10 build 18356.21 (19H1) now in the Slow ring

Microsoft fixes problem blocking devices from upgrading to build 18362 with build 18356.21.

Microsoft is now rolling out Windows 10 build 18356.21 as update KB4496796 for devices in the Slow ring of the Windows Insider Program. This is the preview build number 40 releasing to testers as part of the 19H1 development, and it’s available to resolve the issue which was prevent devices with build 18356.16 to upgrade to build 18362.

After installing the update KB4496796 on your computer running the build 18356.16, the version number will bump to build 18356.21, and in a few days, Windows 10 build 18362 should download and install automatically on your computer.

Download Windows 10 build 18356.21

Although there are no ISO files for Windows 10 build 18356.21, the update is available immediately through the Slow ring. This preview build will download and install automatically on your device, but you can always force the update from Settings > Update & security > Windows Update, and clicking the Check for updates button.

Warning: This is a pre-release version of Windows 10, and it’s not recommended to install on your primary machine. If you’re planning to test this build, make sure to create a backup of your files before proceeding.

You can also check out these resources:


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].