Microsoft has confirmed a problem with the new Windows 11 May 2026 update that causes error code 0x800f0922 on some computers running versions 24H2 and 25H2.
The update starts installing but fails when the computer restarts, then undoes the changes and shows the message "Something didn’t go as planned.
Undoing changes" because there is not enough free space on a special boot part of the hard drive (only 10 MB or less available).
To fix it, restart your computer, go to Settings > Windows Update, and click Check for updates.
This quick fix from Microsoft works for most people, and the company is working on a permanent solution for a future update.