Microsoft has released cumulative update KB5124140 (Build 26220.9492) for Windows 11, version 25H2 for Insiders in the Beta Channel.
- Automatic captions. A setting has appeared that allows screen reader audio to be included in captions. It is disabled by default, and Automatic captions do not transcribe the speech of Narrator, JAWS, and NVDA, showing only microphone and system audio.
- Hyper-V. Fixed an issue where apps with virtual machines managed by the Host Compute Service (HCS) could not work with host shared folders through Plan9: folders opened from a Windows PC did not appear in the Linux guest system or became unavailable.
- Other. Fixed an issue where backup in File History unexpectedly ended with a message that no suitable drives were found.
Installation via Windows Update: Go to Settings > Windows Update and click Check for updates. A restart of the computer will be required to complete the installation.
| Feature / Change | Performance Increase or Decrease | Optimization | PC Operation Speed | Gaming Optimization |
|---|---|---|---|---|
| Automatic captions — new setting to include screen reader audio (Narrator, JAWS, NVDA) in captions, disabled by default; speech of screen readers is not transcribed, only microphone and system audio | ⚪ No measurable change (0%) in raw performance | 🟡 Low (adds an optional accessibility pipeline, negligible overhead while disabled by default) | ⚪ No impact (0%) on general PC speed | ⚪ No impact (0%) on gaming |
| Hyper-V — fixed an issue where apps with virtual machines managed by the Host Compute Service (HCS) could not use host shared folders through Plan9; folders opened from a Windows PC did not appear in the Linux guest or became unavailable | 🟢 Moderate improvement (functional fix, not raw FPS/throughput gain) | 🟢 High (restores intended shared-folder functionality in VM workflows) | 🟡 Low–Medium (indirect: fewer retries/hangs when accessing shared folders) | ⚪ No impact (0%) on gaming |
| Other — fixed an issue where File History backup unexpectedly ended with a message that no suitable drives were found | ⚪ No measurable performance change (0%) | 🟢 Medium (restores reliable backup operation, avoids failed runs) | 🟡 Low (indirect: no more aborted backup processes) | ⚪ No impact (0%) on gaming |
Find and Change Settings
| Setting | Where to find | How to change |
|---|---|---|
| Automatic captions — include screen reader audio | Settings > Accessibility > Captions | Open Settings > Accessibility > Captions and turn on the option to include screen reader audio in captions. The setting is disabled by default. |
Official announcement on the Microsoft website.
The last 10 Windows updates:
| Update | Build | Version | Windows | Channel | Date |
|---|---|---|---|---|---|
| KB5124006 | 28000.3086 | 26H1 | Windows 11 | Preview | 2026-09-22 |
| KB5124010 | 26200.9550 | 26H2 | Windows 11 | Preview | 2026-09-22 |
| KB5124138 | 28120.3032 | 26H1 | Windows 11 | Experimental | 2026-09-18 |
| KB5124140 | 26220.9492 | 25H2 | Windows 11 | Beta | 2026-09-18 |
| KB5124137 | 26340.9502 | 26H2 | Windows 11 | Experimental | 2026-09-18 |
| KB5129242 | 22631.7584 | 23H2 | Windows 11 | Stable | 2026-09-14 |
| KB5129236 | 19045.7727 | 22H2 | Windows 10 | Stable | 2026-09-14 |
| KB5129195 | 26300.9457 | 26H2 | Windows 11 | Stable | 2026-09-14 |
| KB5129194 | 28000.2956 | 26H1 | Windows 11 | Stable | 2026-09-14 |
| KB5124115 | 26220.9472 | 25H2 | Windows 11 | Beta | 2026-09-11 |