Windows bugs and fixes October 3 2026: status

What broke after the recent Windows 11 updates?

KB5120998 can leave Windows 11 at a black screen after sign-in, gHacks said on September 27, 2026. The desktop session fails to load because Windows Explorer does not start, according to the same gHacks report dated September 27, 2026.

The affected versions are Windows 11 24H2, 25H2 and 26H1, while Server editions are not affected, gHacks said on September 27, 2026. Reports have primarily involved Azure Virtual Desktop hosts using FSLogix, and the problem appears more often with some existing user profiles, according to gHacks on September 27, 2026. The symptoms include a black screen, no automatically loaded desktop and Windows Explorer crashes in the application event log, Betanews reported on September 26, 2026.

There is a naming discrepancy around the triggering Windows 11 bug. BetaNews named KB5120996 and KB5124010 on September 26, 2026, while gHacks named KB5120998 and subsequent updates on September 27, 2026. I cannot reconcile those KB references from the published reports. The practical symptom and Microsoft’s response are otherwise consistent across both dated accounts.

Has a permanent Windows update fix shipped?

No permanent fix has shipped, gHacks reported on September 27, 2026. Microsoft said a resolution would arrive in a future Windows update, but it did not provide a date or name the update, according to gHacks on September 27, 2026.

The immediate personal-PC workaround is to open Task Manager and run explorer.exe, Finance Biggo reported on September 28, 2026. That forces the desktop to load. The cost is manual recovery instead of automatic desktop loading.

Managed devices have version-specific Known Issue Rollback packages. Windows 11 26H1 uses KB5124006 260924_20071 Known Issue Rollback, while Windows 11 24H2 and 25H2 use KB5124010 260924_20021 Known Issue Rollback, gHacks said on September 27, 2026. Administrators must install and configure the applicable Group Policy package and restart the device, according to gHacks on September 27, 2026. The policy disables the responsible change until Microsoft releases a resolution. Its cost is administrator work, a restart and temporary removal of that change.

Finance Biggo said on September 28, 2026, that internet-connected devices can receive a partial rollback within up to 24 hours. Enterprise environments where Group Policy disables KIR need the dedicated installer, according to the same report dated September 28, 2026.

Which problems remain on Windows 11 26H2?

Windows 11 26H2 carries USB audio, domain trust, black-screen and AC-3 issues, Microsoft Learn listed on October 3, 2026. The Windows known issues page marks the USB audio, domain trust and black-screen entries as mitigated, according to Microsoft Learn on October 3, 2026.

Some USB Audio Class 1.0 devices can display Code 10 or fail in multichannel audio modes after the Sept. 8 update, Microsoft Learn said on October 3, 2026. Domain-joined devices can lose their secure trust relationship with the domain, leaving some Credential Guard protected machine accounts unable to sign in interactively with valid domain credentials, according to Microsoft Learn on October 3, 2026.

Applications that require Windows AC-3 decoding can fail to launch, close without warning or stop when playing music after KB5124010 and later updates, Microsoft Learn said on October 3, 2026. Microsoft said many modern applications use their own audio decoding components and are unlikely to encounter the problem, according to the same page dated October 3, 2026.

The AC-3 resolution has not shipped. Microsoft Learn said on October 3, 2026, that Microsoft was working on a resolution for a future Windows update and would provide more information when available. I read mitigated as risk reduction, not proof of a permanent repair.

Should you install Windows 11 26H2 now?

People determined to avoid the listed issues should wait before installing 26H2, PCWorld said on September 30, 2026. PCWorld also said on September 30, 2026, that Microsoft had not provided details about when the remaining fixes would arrive.

Windows 11 26H2 began rolling out on September 29, 2026, Thepcenthusiast reported on September 30, 2026. Microsoft uses a phased rollout, so every compatible PC will not receive the offer immediately, according to Thepcenthusiast on September 30, 2026. I would not force the upgrade if Windows Update has not offered it.

Eligible Windows 11 24H2 and 25H2 computers receive 26H2 as an enablement package after installing the September 22, 2026 KB5124010 preview update or a later cumulative update, Thepcenthusiast said on September 30, 2026. The upgrade requires a single restart, according to the same report dated September 30, 2026. Windows 11 26H1 cannot upgrade directly because it uses a different Windows core, Thepcenthusiast reported on September 30, 2026.

For the preceding daily checkpoint, see Windows bugs and fixes October 2 2026: status.

What can you do today?

Start explorer.exe through Task Manager when the desktop stays black, Finance Biggo advised on September 28, 2026. That workaround restores access to the desktop but does not remove the underlying update problem, according to Finance Biggo on September 28, 2026.

On an IT-managed Windows 11 26H1 device, ask the administrator to deploy KB5124006 260924_20071 Known Issue Rollback, gHacks said on September 27, 2026. On managed Windows 11 24H2 or 25H2 devices, the applicable package is KB5124010 260924_20021 Known Issue Rollback, according to gHacks on September 27, 2026. A restart is required after the policy is configured.

Do not force Windows 11 26H2 when Windows Update has not offered it, following Thepcenthusiast’s phased-rollout guidance published September 30, 2026. If an application closes while using AC-3 audio, trying a modern application with its own decoder may avoid the Windows component, based on Microsoft Learn’s description dated October 3, 2026. The cost is changing applications or workflows, and Microsoft has not named a shipped AC-3 fix.

For USB Audio Class 1.0 failures or domain trust trouble, check the Microsoft Learn 26H2 status page dated October 3, 2026 before changing unrelated settings. The published page records those problems as mitigated, but it does not name a permanent fix build in the supplied entries.