On Thursday, Microsoft released the biggest Windows 11 update of the year with a resizable Start menu, a movable taskbar, and Bing/bloat-free Windows Search. Unfortunately, Windows Latest found that it breaks the mouse cursor, resets the wallpaper, causes issues with fonts, and now Microsoft says it is investigating. We are talking about Windows 11 KB5120998, which updates the operating system to build 26200.9278 in version 25H2 and to build 26100.9278 in version 24H2. It’s an optional update, so it’s not downloaded or installed automatically, but you don’t need to join any particular trial program to see it. It appears on all PCs by default. As soon as Windows 11 KB5120998 was released, some users started reporting a bug where the mouse cursor does not appear at all or appears too big or too small. In other cases, the mouse cursor was reset to its default values, either in terms of color or size. Until now, Microsoft maintained radio silence, and based on the growing number of reports, we were convinced that it was much more widespread than the usual chatter. Now, Microsoft has quietly updated its release notes to confirm that the mouse cursor settings are indeed breaking after the Windows update. “Microsoft has received reports that mouse cursor customization settings are being changed or reverted to certain standard settings,” Microsoft warned in updated release notes spotted by Windows Latest. “This occurs after installation of Windows updates released August 27, 2026 (KB5120998) and later.” Microsoft says it is investigating the reports and trying to determine if the problem is actually due to Windows Update. However, all signs suggest that it is actually caused by the optional update, as the issue appeared the moment the update finished installing and disappeared when users removed it. It’s the usual PR language Microsoft has used lately when talking about Windows Update problems, so I expect a more formal acknowledgment in the coming days, followed by a rollback of the change that caused the problem or an emergency out-of-band update that fixes the broken cursor. Windows 11 KB5120998 may alter custom cursor size, color, and schemes. I contacted an affected user who tried everything from resetting the Windows Registry to running DISM and resetting the mouse cursor to default settings, but he still had a giant cursor on his desktop. As soon as they uninstalled Windows 11 KB5120998, the cursor issue resolved itself. And that seems to be the case for everyone who reported cursor issues after installing the big optional Windows 11 update. According to Microsoft, and based on reports Windows Latest has seen, here’s what could happen when you install Windows 11 KB5120998 and are unlucky: Your cursor animations could look broken and the appearance could change, especially if you use a custom scheme, including those provided by Microsoft in the official Windows setup. Some cursors that were set by default are being replaced with larger cursors. If you had a white cursor, it could become big and black, and vice versa. If you use a custom outline or cursor animations, they might revert to the standard settings. I don’t think it’s a major problem compared to a big cursor appearing out of nowhere. If you try to restore a smaller or normal cursor, you could go back to the broken one, as the settings simply don’t save. Unfortunately, if you are experiencing these issues, you will need to manually remove Windows 11 KB5120998 as no other solution seems to work. You need to open Settings > Windows Update > Update History > Uninstall, locate KB5120998, and click Uninstall. Since Windows 11 KB5120998 is an optional release, you can remove it without missing the security fixes in this month’s Patch Tuesday release. It’s unclear why and how the Windows 11 update broke the cursor because most of the changes in the update were to the Start menu, Search, taskbar, and File Explorer, except for a slightly related improvement where the update improved “touchpad reliability on some devices.” I don’t think that could have caused the problem. Wallpapers reset after August update. Windows Latest noted that there is another bug where your desktop wallpaper settings are never saved and you have a black screen. It keeps rebooting with every reboot and there are many similar complaints in the Feedback Center. I was able to reproduce this issue and it fixed itself after removing the update. “My desktop wallpaper turned black after installing the latest Windows 11 updates in August 2026 and every time I reboot, it turns black,” one user wrote in a post on Feedback Hub, and there are dozens of similar complaints on our forum/comments section and platforms like Reddit. There is a third bug where the font can be blurry on certain systems, but I don’t think this one is as widespread as the other two. Microsoft has not yet acknowledged problems with the wallpaper. Windows 11 KB5120998 is a “preview” update, but not the kind you might think. Some of you might argue that it is a “preview” update and that no one should have installed it on their “production” PCs. But it’s not the kind of “preview” update that some would think it is. The update is listed as “preview”, but it is not a beta version. It is a production version and all the changes it contains will be shipped with the next Patch Tuesday. KB5120998 is labeled as a “preview update,” but it is not a technical release of the Windows Insider Preview. Microsoft uses similar terminology for both, but optional updates like KB5120998 are offered for production PCs and are simply not downloaded automatically unless you have enabled the option to get the latest updates as soon as they are available. Microsoft has never recommended against making optional updates, as they are essentially for everyone who wants to try out new features before the upcoming Patch Tuesday release, which would come with these changes anyway, along with security fixes. “The monthly rollup preview is product-specific and addresses new, non-security-related updates, and includes fixes from the latest monthly rollup,” Microsoft said in a support document describing the “preview updates.” “This monthly rollup preview will be displayed under the Quality Monthly Rollup Preview heading when you download or install it.” Everything included in these optional monthly “preview” updates ships with the upcoming Patch Tuesday release, including the cursor bug if Microsoft doesn’t rush to fix it. Optional Windows preview updates are typically as stable as Patch Tuesday releases, and they were about the same when Windows 10 was the flagship operating system. However, in recent years, as Microsoft laid off most members of its Quality Assurance team and began to rely more on AI, Windows quality has been trending downward. Support original journalism. Windows Latest depends on readers like you. Make us your preferred source on Google Discover and Google Search, and help our independent reporting reach more people.
