Build 26120.670: Windows Insider Dev Channel, May 2024. File Explorer network locations and Windows Update installation fixes

Fixes File Explorer and Windows Update problems, adjusts a DNS validation limit, and addresses issues affecting domain controllers and protected Windows features.

Does it affect you? Applies to: Devices enrolled in the Windows Insider Program in the Dev Channel.

This is a test build for people in the Windows Insider Program. Features in it can change, be removed, or never reach regular Windows releases.

What changes

Fixes 4 changes

File Explorer

For: everyone in the Dev Channel

The Network Locations heading appears again in the This PC section of File Explorer.¹

Domain controllers

The amount of authentication network traffic on domain controllers might otherwise increase.²
Addresses an issue that might affect domain controllers (DC): NTLM authentication traffic might increase.

Windows Update

For: everyone in the Dev Channel

A Windows update can complete installing when your device needs to restart more than once.³
Addresses an installation failure that occurs when the device must restart more than once.

Virtual Secure Mode

For: devices using Virtual Secure Mode scenarios

Some VPN, Windows Hello, and Windows security features might otherwise fail.⁴
Addresses an issue that might affect Virtual Secure Mode (VSM) scenarios. These include VPN, Windows Hello, Credential Guard, and Key Guard.

Improvements 2 changes

General

Gradual rollout

For: Dev Channel Insiders with the latest-updates toggle on

A small set of general improvements and fixes is rolling out to Insiders.⁵

DNS validation

For: DNS Server administrators and devices using a recursive resolver

A DNS validation limit is now 1,000 checks. Each check validates one label in one iteration.⁶
The NSEC3 validation limit in a recursive resolver is 1,000 computations; one computation equals validation of one label with one iteration.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released: 2024-05-17
Type: Windows Insider build

Version	Build	Channel
—	26120.670	Dev Channel

Security

No vulnerabilities are listed for this update.

Sources

Windows Insider Blog

Updated Oct 27, 2026

Cited passages from Microsoft's official notes (6)

1. Fixed an issue where the Network Locations header was missing in the This PC section of File Explorer. blogs.windows.com
2. This update addresses an issue that might affect domain controllers (DC). NTLM authentication traffic might increase. blogs.windows.com
3. This update addresses an issue that affects the installation of a Windows update. It fails to complete. This occurs when you have to restart your device more than once. blogs.windows.com
4. This update addresses an issue that might affect Virtual Secure Mode (VSM) scenarios. They might fail. These scenarios include VPN, Windows Hello, Credential Guard, and Key Guard. blogs.windows.com
5. This update includes a small set of general improvements and fixes that improve the overall experience for Insiders running this build on their PCs. blogs.windows.com
6. This update affects next secure record 3 (NSEC3) validation in a recursive resolver. Its limit is now 1,000 computations. One computation is equal to the validation of one label with one iteration. blogs.windows.com

Checked automatically: 8 of 8 checks passed, 6 quoted passages

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 5/5, clarity 5/5, 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