A weekend with no fix for the KB5120998 black desktop on Windows 11 (September 5, 2026)
Chapters
What a quiet Saturday actually means
Nothing new broke on the record on September 5, 2026. I could not verify a single new Windows bug report published that day, and a Saturday in the middle of a servicing month is a day for reading what is still open rather than what is new.
What was still open: two KB5120998 known issues, the non-English mouse customization reset and the lost desktop background. Both carry an originating update date of August 27, 2026 and neither was closed. The September security update was three days out.
Neither half is new here. The black desktop was drawing user reports before Microsoft had an entry for it, which is where the August 29 post left it, and the acknowledgment arrived on September 2, 2026. What is worth recording about September 5 is that nothing moved.
TL;DR
The most reported Windows 11 defect going into the weekend of September 5, 2026 was still the KB5120998 pair, a solid black desktop and a cursor that will not stay changed, both sitting open on Microsoft's release health dashboard at Microsoft Learn with an originating update date of August 27, 2026. I could not verify a new Windows bug report published on September 5, 2026, and the freshest coverage was still from September 4. Nothing shipped over the weekend: no workaround for the desktop background issue and no fix for either half.
- Nothing new was published on September 5, 2026 that I could verify. Both KB5120998 known issues stayed exactly where they were.
- Microsoft's wording for the desktop half: attempting to manually restore customized settings does not work.
- No workaround is listed for the desktop background issue, and the affected platforms are Windows 11 25H2 and 24H2.
- KB5120998 is a non-security preview, so removing it costs features rather than patches.
- The August .NET Framework update that broke WPF printing was also still open, with only a workaround that weakens security.
The desktop half, unchanged
Microsoft's wording had not moved. Attempting to manually restore customized settings does not work, the affected platforms are Windows 11 25H2 and 24H2, and no workaround is listed for the desktop background issue.
Machines also kept acquiring the fault days after installing the update, because the feature behind it arrives by phased rollout. Windows Latest advised on September 4, 2026 that people avoid KB5120998 until it is patched, noted that the fix was expected with the September 8, 2026 Patch Tuesday release, and reported that the feature cannot be rolled back once it has reached a device.
What removing the update costs
KB5120998 is the August 27, 2026 preview update for Windows 11 25H2 and 24H2, OS builds 26200.9278 and 26100.9278, per Microsoft Support. It is non-security, so uninstalling it leaves no security patches missing. That is the one piece of good news in this story.
What it does give up is what the update brought: a repositionable taskbar, a smaller taskbar size option, selectable Start menu sizing, and administrator protection off by default. On a weekend with no fix, that is the whole trade: a working desktop background and a working pointer, against four preview changes. Removing the update is the community remedy for both issues rather than a Microsoft workaround, and Microsoft has published no workaround for either one.
| Known issue | Opened | Microsoft workaround | State on September 5, 2026 |
|---|---|---|---|
| Mouse customization is reset on non-English Windows devices | August 28, 2026 | None published | Open, no fix |
| Desktop background settings are lost or reset on some devices | September 2, 2026 | None published | Open, no fix |
What else was still open
The August .NET Framework update that broke WPF printing was also still unfixed on September 5, 2026. The only workaround was an AppContext switch that weakens security, per The Register on August 25, 2026. Eleven days after that piece there was nothing better to offer anyone who prints from a WPF application.
Two open regressions in the same servicing month, one in personalization and one in printing, both waiting on the same thing: a shipped fix, on Microsoft's schedule rather than anyone else's.
What you can do today
1. If KB5120998 is not installed, leave it that way until the known issues close. It is optional and non-security.
2. If it is installed and nothing has gone wrong, do not treat that as immunity. The phased rollout can still reach your machine.
3. If the desktop is black or the cursor is wrong, do not spend the weekend re-applying settings. Microsoft documents that as ineffective for both issues.
4. If you want the desktop back now, uninstall it: Settings, then Windows Update, then Update history, then Uninstall updates, select KB5120998, then restart. Accept that you lose the four preview features.
5. Note your OS build from winver before Tuesday, September 8, 2026. When the monthly update arrives, that is what tells you whether the new build is on the machine.
6. Check the known issue entries after the monthly update installs, rather than assuming it covered these two. Neither had a published fixing build as of September 5, 2026.
Frequently asked questions
Is KB5120998 safe to skip?
It is an optional, non-security preview update for Windows 11 25H2 and 24H2, so skipping it leaves no security patches uninstalled. What you skip is the features it carries, including the repositionable taskbar and the Start menu sizing options.
Will re-applying my wallpaper fix the black desktop?
No. Microsoft's wording for this issue is that attempting to manually restore customized settings does not work, because the settings fail to load regardless of the value you choose.