Ten days on, KB5120998 is still resetting cursors and wallpapers on Windows 11 (September 6, 2026)
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TL;DR
Ten days after KB5120998 shipped, Windows 11 users were still discovering for the first time that it resets the mouse cursor and turns the desktop wallpaper a solid color: a question asked at 13:34 UTC on September 6, 2026 on Microsoft Q&A describes both symptoms on build 26200.9278. The answer 33 minutes later was to uninstall the update and switch off early update delivery. No fix had shipped as of September 6, 2026, and both symptoms refuse manual restoration.
- The report, in the user's words: the cursor had changed to an old Windows cursor, not the default Windows 11 one, and the desktop wallpaper turned into a solid color.
- The answer at 14:07 UTC the same day: uninstall KB5120998 and disable getting the latest updates as soon as they are released.
- Microsoft tracks this as two separate known issues, the non-English mouse customization reset and the lost desktop background.
- Reports were still arriving fresh ten days in because the phased rollout kept reaching new machines.
- Turning off early update delivery means new features reach you later, on the monthly security update instead.
What arrived on September 6
The question was asked at 13:34:45 UTC on September 6, 2026, on KB5120998, the preview update for builds 26200.9278 and 26100.9278. The symptom, verbatim: the cursor had changed to an old Windows cursor, not the default Windows 11 one, and the desktop wallpaper turned into a solid color. Both halves of the same update's personalization failure, on one machine, described by someone meeting them for the first time.
The date is the point of this post. The update shipped on August 27, 2026 and both issues were acknowledged by September 2, 2026, yet on September 6, 2026 it was still landing on people as a fresh surprise. The phased rollout is why: it kept reaching new machines, so fresh reports kept arriving ten days after the release. I covered the cursor half the day its entry opened, in the August 28 post.
The advice given, and what it costs
The answer, posted at 14:07:08 UTC the same day, prescribed two steps: uninstall KB5120998, and disable getting the latest updates as soon as they are released, in Windows Update settings, so that the optional preview does not arrive again.
The second step has a cost worth stating. Disabling that setting is what stops the optional preview arriving again, and it also means new features reach you later, on the monthly security update instead. For a PC where a working pointer and a working desktop matter more than early features, that is a fair trade, and it is a setting you can turn back on once these issues are closed.
Two known issues, not one
The answer named both entries Microsoft tracks: mouse customization reset on non-English devices, and desktop background reset to a solid black color with manual restoration failing. They arrived in one update, and they are recorded and worded separately.
For anyone troubleshooting, the consequence is that there is no single setting to repair. Both are load failures, so the values you pick are stored and then ignored, and the guidance on the thread is explicitly not to attempt manual cursor or wallpaper restoration, because it is documented as ineffective.
| Symptom | Microsoft's known issue | State as of September 6, 2026 |
|---|---|---|
| Cursor reverts and will not stay changed | Mouse customization is reset on non-English Windows devices | Acknowledged, no fix |
| Desktop background turns a solid color | Desktop background settings are lost or reset on some devices | Acknowledged, no fix |
File History is still not recording versions
A separate update related failure got another reply on September 6, 2026. The discussion on Microsoft Community Hub, opened on August 30, 2026, reports File History still copying files while the Last Backup timestamp never moves and new files show no previous version available under Properties. One responder reported the File History service failing at startup with an ESENT database error of -621.
I covered that thread in the August 31 post. It is worth pairing with the personalization bugs for one reason: a black desktop announces itself the moment you log in, while a backup that has silently stopped recording versions announces itself only when you need a version back.
What you can do today
1. Confirm the update. Open Settings, then Windows Update, then Update history, and look for KB5120998.
2. Do not attempt manual cursor or wallpaper restoration. It is documented as ineffective, and it is an hour you will not get back.
3. If the personalization matters, uninstall it: Settings, then Windows Update, then Update history, then Uninstall updates, select KB5120998, then restart.
4. Switch off getting the latest updates as soon as they are released, in Windows Update, so the optional preview does not return. Accept that features then reach you on the monthly update instead.
5. While you are in there, check File History: right click a file you edited this week, open Properties and look at Previous Versions. If there are none, that is the second problem in this post, and it is quieter than the first.