Microsoft confirms Windows 11’s May 2026 update is failing to install with error 0x800f0922 and outlines a mitigation for affected PCs
Microsoft has confirmed that Windows 11’s May 2026 Security Update is failing to install on some devices with error code 0x800f0922. The issue affects systems running versions 24H2 and 25H2 following the installation of update KB5089549, which was released on May 12, 2026.
The installation failures occur during the reboot phase of the update process, typically when the installation is approximately 35 percent complete. Microsoft has identified the root cause: the problem occurs on devices with limited free space in the EFI System Partition (ESP), specifically those with 10MB or less of available storage.
While a permanent fix is in development, Microsoft has already shipped a workaround for affected users. The mitigation provides an immediate solution for systems experiencing this installation failure, allowing users to complete the security update without waiting for the full patch.