KB5120998

August optional preview · 2026-08-27

Curated snapshot · 2026-10-25. This small collection is not a complete risk assessment. No matching report does not mean an update is safe. Automatic monitoring is not connected.

Update identity

Windows versions: 24H2 / 25H2
OS builds: 26100.9278 / 26200.9278
Release type: Preview
Released: 2026-08-27
Last checked: 2026-10-25

Read the Microsoft KB article

Issues & evidence

3 results

KB5120998ResolvedOfficial · C3

Black screen after sign-in on virtual desktop hosts

After the August 2026 preview and subsequent updates, some users saw a black screen after sign-in with the desktop session failing to load; Explorer crashes appear in application event logs.

Azure Virtual Desktop / FSLogix · Windows 11 24H2 / 25H2 · Architecture unspecified

KB5120998ResolvedOfficial · C3

Custom mouse pointers revert unexpectedly

Customized pointers can revert on non-English Windows installations.

Mouse personalization · Windows 11 24H2 · Architecture unspecified

KB5120998ResolvedOfficial · C3

Desktop background resets to a solid color

Some installations lose their selected desktop background.

Desktop personalization · Windows 11 24H2 · Architecture unspecified

Resolution links

No resolving links captured in this collection.

An update that supersedes another update does not automatically resolve every associated issue.