Windows Update: Installation may fail due to insufficient EFI space
Windows security updates from May are failing on some systems. The cause is insufficient space on the EFI partition.
(Image: Dirk Knop / heise online)
Last week's Windows updates cannot be installed on some Windows 11 systems. An error code “0x800f0922” is related to the EFI system partition. Possible countermeasures should help.
Microsoft acknowledges the problem in the Message Center of the Windows Release Health notes. The security updates from May may generate the error code “0x800f0922.” The issue affects devices with insufficient space in the EFI system partition. This is particularly the case when the free space is only 10 MB or less. Microsoft has confirmed the issue for Windows 11 24H2 and 25H2.
On affected devices, the installation may proceed through the initial phases but then fail during the reboot phases at around 35 to 36 percent progress, the company explains. The installation then starts a rollback and the message “Something didn’t go as planned. Undoing changes” appears. In the file “C:\Windows\Logs\CBS\CBS.log,” log entries such as “SpaceCheck: Insufficient free space”, “ServicingBootFiles failed. Error = 0x70” or “SpaceCheck: <value> used by third-party/OEM files outside of Microsoft boot directories” can be found in such cases.
Possible countermeasures
Affected users can help themselves in two ways, Microsoft further explains. They can make changes to the registry – Microsoft advises creating a backup first – and add the DWORD key “EspPaddingPercent” with the value “0” in the path “HKLM\SYSTEM\CurrentControlSet\Control\Bfsvc.” At the administrative command prompt (click Start, type “CMD,” and select “Run as administrator”), according to Microsoft, the command reg add “HKLM\SYSTEM\CurrentControlSet\Control\Bfsvc” /v EspPaddingPercent /t REG_DWORD /d 0 /f does this. After a restart, the update should be installable.
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The second form of assistance is a Known Issue Rollback (KIR), where the update component in question is simply not distributed. Microsoft has set this up for all unmanaged devices and machines of private end customers, so it is primarily aimed at administrators in business environments. Restarting the computers can help the KIR take effect more quickly. IT managers can find a download link to a group policy in the Message Center article to implement this in their network.
(dmk)
