Microsoft has acknowledged an issue affecting the installation of Windows 11’s May 2026 Update (KB5089549), which has been encountering errors such as 0x800f0922, 0x80240069, and 0x80240031. In response, the tech giant is implementing an emergency server-side update aimed at resolving these installation hurdles.
The KB5089549 update is a mandatory release intended to install automatically across all compatible PCs. However, some users have reported difficulties during the installation process. According to an updated support document from Microsoft, the installation of the May 2026 Update initiates upon clicking the download button, typically followed by a reboot to complete the changes. Users may find themselves facing a spinning circle screen, indicating progress, but installation can stall around the 35-36% mark, prompting Windows to roll back the changes. In such cases, users may encounter a message stating, “something didn’t go as planned. Undoing changes,” before being returned to the desktop.
Why is the Windows 11 KB5089549 update failing due to 0x800f0922?
Investigations by Windows Latest reveal that the installation failures are particularly affecting devices with limited EFI (Extensible Firmware Interface) partition space, suggesting that this issue may be more widespread than initially thought. Users encountering the error code 0x800f0922 in Windows Update will find corresponding entries in the Event Viewer log, indicating insufficient free space and potential conflicts with third-party files.
SpaceCheck: Insufficient free space ServicingBootFiles failed. Error = 0x70 SpaceCheck: used by third-party/OEM files outside of Microsoft boot directories Workaround
The EFI System Partition (ESP) is a critical component of Windows installations, typically occupying no more than 100MB of disk space. This partition stores essential boot files, and while it is generally hidden to prevent accidental alterations, it can become congested due to leftover files from firmware updates or the installation of multiple operating systems. Consequently, when the available space dips below the required threshold, the installation of KB5089549 may fail.
Users with less than 10MB of free EFI storage may face additional complications during the update process. Unfortunately, accessing this hidden partition through File Explorer is not possible, but a PowerShell script can provide insights into the current EFI storage status. For those interested in checking their EFI storage before proceeding with updates, the following PowerShell command can be executed:
Get-Partition | Where-Object GptType -eq '{c12a7328-f81f-11d2-ba4b-00a0c93ec93b}' | Get-Volume | Format-List Size, SizeRemaining
In one user’s account, they described their PC entering a boot loop while attempting to install KB5089549, with the system restarting multiple times without completing the update. Another user echoed similar frustrations, detailing how their installation reached 100% before encountering an error that prompted a rollback. Despite attempts to troubleshoot, they found no resolution through the Windows troubleshooter.
Microsoft rolls out an emergency update to address the May 2026 update issues
To alleviate these installation challenges, Microsoft has advised users to consider increasing the size of the ESP by modifying the Windows Registry. However, with the recent server-side update already addressing the issue, this step may no longer be necessary. Microsoft confirmed that the Known Issue Rollback (KIR) has been implemented, automatically propagating the resolution to consumer and non-managed business devices. Users are encouraged to restart their Windows devices to expedite the application of this fix.
As per Microsoft’s latest communication, there are no additional bugs reported, indicating a denial of unverified claims regarding internet connectivity issues. Users are advised to reboot their PCs several times before checking for updates to ensure the resolution is effectively applied.
