The Update BureauKB5064080: Cumulative update for Windows 11, version 23H2, August 2025. Windows Backup reaches general availability; Explorer and input fixes
In short
Windows Backup for Organizations is generally available, and the preview fixes File Explorer, input, and other problems. Standard users might still see unexpected UAC prompts during MSI repairs; KB5065431 addresses the issue.
Does it affect you? Applies to: Devices running Windows 11, version 23H2, including x64 and Arm64 devices.
What changes
Fixes 13 changes
Copilot
- The Copilot key works more reliably, and users can restart Copilot after using the key.1
Country and Operator Settings Asset (COSA)
Verified in package
For: devices using certain mobile operators
- Profiles for some mobile operators are brought up to date.2
Device management
- Removable storage policies correctly block external devices such as USB flash drives.3
Family Safety
Verified in package
For: devices with Family Safety enabled
-
Blocked apps show the expected approval prompt when Family Safety settings are enabled.4
Fixes the missing “Ask to Use” approval prompt.
File Explorer
2 items
File sharing
For: devices accessing SMB shares over QUIC
-
Accessing files on some network shares no longer causes unexpected delays.7
Addresses delays when accessing files on an SMB share over QUIC.
File system
For: devices using ReFS
-
The system is less likely to stop responding when file deduplication and compression are both enabled.8
Addresses an issue in Resilient File System (ReFS) when deduplication and compression are enabled simultaneously.
Input
2 items
-
Some extended characters, including rare Chinese symbols, display correctly in Windows text boxes.9
The fix supports GB18030-2022 requirements.
-
Some extended characters no longer appear as empty boxes with the Chinese (Simplified) IME.10
Addresses an issue with the Chinese (Simplified) Input Method Editor (IME).
Narrator
For: users of Narrator
-
Narrator reads the name of the facial recognition protection checkbox correctly.11
The checkbox is under Facial recognition (Windows Hello).
Network connectivity
- Wi-Fi can reconnect automatically again after a Group Policy update.12
Remote Desktop
Verified in package
For: Remote Desktop Services users
-
Cameras appear in remote sessions after they are added or removed.13
Fixes camera recognition in Remote Desktop Services (RDS) environments.
Improvement 1 change
Servicing stack
-
The component that installs Windows updates gets quality improvements.14
Includes servicing stack update KB5064743, build 22621.5973.
New feature 1 change
Windows Backup for Organizations
-
Windows Backup for Organizations is now generally available for organizations.15
The service supports backup and restore during device transitions, Windows 11 upgrades, and deployments of AI-powered PCs.
Known issues
-
Unexpected User Account Control (UAC) prompt when doing MSI repair operations
On this update, standard users might see unexpected UAC prompts during MSI repairs and related operations. Microsoft lists this as a known issue for KB5064080.16
How to apply the workaround WorkaroundInstall KB5065431; Microsoft says it addresses this issue.16
Technical details
Data sheet · Security · Downloads · Components Click to collapse or expand
Data sheet
- Released
- 2025-08-26
- Classification
- Updates
- Type
- Cumulative update
- Restart
- Required
- Replaces
-
KB5066189, KB5063875, KB5062663, KB5062552
+37 earlier
KB5060826, KB5060999, KB5062170, KB5058502, KB5058405, KB5055629, KB5058919, KB5055528, KB5053657, KB5053602, KB5052094, KB5051989, KB5050092, KB5050021, KB5048685, KB5046732, KB5046633, KB5044380, KB5044285, KB5043145, KB5043076, KB5041587, KB5041585, KB5040527, KB5040442, KB5039302, KB5039212, KB5037853, KB5037771, KB5036980, KB5036893, KB5035942, KB5035853, KB5034848, KB5034765, KB5034204, KB5034123 - Replaced by
- KB5065431
| Version | Build | Channel |
|---|---|---|
| 23H2 | 22631.5840 | General availability |
| 23H2 | 22631.5840 | Release Preview Channel |
Security
No vulnerabilities are listed for this update.
Downloads (Microsoft Update Catalog)
x64
23H2
896.2 MB
Arm64
23H2
1.0 GB
Updated components
1,549 files changed since the previous update for the same versions.
| Top changed components | Files |
|---|---|
| Settings | 121 |
| Bluetooth | 37 |
| File Explorer and shell | 22 |
| Graphics and display | 18 |
| Hyper-V and virtualization | 17 |
| Networking | 17 |
| Search | 14 |
| Kernel | 7 |
| Emoji and input | 6 |
| Remote Desktop | 6 |
| Security and sign-in | 6 |
| Audio | 5 |
Verified in package: changed files confirm Country and Operator Settings Asset (COSA), Family Safety, Remote Desktop.
Sources
Updated
Cited passages from Microsoft's official notes (16)
-
1.
Fixed: Improved the Copilot key’s reliability and resolved an issue that prevented users from restarting Copilot after using the key.
support.microsoft.com -
2.
This update brings profiles up to date for certain mobile operators.
support.microsoft.com -
3.
An issue where the removable storage policy didn’t correctly block external devices such as USB flash drives.
support.microsoft.com -
4.
An issue where the “Ask to Use” approval prompt didn’t appear when blocked apps were opened. With this fix, apps now show the expected approval prompt when Family Safety settings are enabled.
support.microsoft.com -
5.
File Explorer might unexpectedly only display a single folder (for example, Desktop), rather than the expected content with recent files and more.
support.microsoft.com -
6.
Syncing more SharePoint sites to File Explorer might slow performance when navigating folders or opening the context menu.
support.microsoft.com -
7.
This update addresses an issue where accessing files on a Server Message Block (SMB) share over Quick UDP Internet Connections (QUIC) might result in unexpected delays.
support.microsoft.com -
8.
This update addresses an issue in Resilient File System (ReFS) where enabling deduplication and compression simultaneously could occasionally cause the system to stop responding.
support.microsoft.com -
9.
This update addresses an issue where certain extended Unicode characters—such as rare Chinese symbols—appeared as blank spaces or incorrect symbols in Windows text boxes.
support.microsoft.com -
10.
This update addresses an issue with the Chinese (Simplified) Input Method Editor (IME) where some extended characters appeared as empty boxes.
support.microsoft.com -
11.
This update addresses an issue where Narrator incorrectly read the name of the Enhance Facial Recognition Protection checkbox under the Facial recognition (Windows Hello) setting.
support.microsoft.com -
12.
This update addresses an issue where Wi-Fi might not reconnect automatically after a Group Policy update.
support.microsoft.com -
13.
An issue where cameras didn’t appear during remote sessions after being added or removed. Newly connected cameras were not recognized in Remote Desktop Services (RDS) environments
support.microsoft.com -
14.
This update makes quality improvements to the servicing stack, which is the component that installs Windows updates.
support.microsoft.com -
15.
[Windows Backup for Organizations] New! Windows Backup for Organizations is now generally available!
support.microsoft.com -
16.
This issue is addressed in KB5065431.
support.microsoft.com
Checked automatically: 8 of 8 checks passed, 16 quoted passages · compared with Microsoft's page on Oct 20, 2026
- Quotes found in the official pages: passed
- Numbers found in the sources: passed
- Vulnerabilities from the dossier only: passed
- Links to allowed domains only: passed
- Every official change covered: passed
- Readable plain text: passed
- Changes confirmed by the file list: passed
- Sources agree: passed
A second AI read the text against the sources: correctness 4/5, clarity 3/5, completeness 5/5. How we work
Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake