When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Windows Server 2025 Insider Preview build 26227 adds a new known issue

windows server insider preview

Microsoft has released the latest Windows Server build for members of the Windows Server Insider Program. The new build number is 26277 and is the same build number for the just-released Windows 11 Canary Channel build. Keep in mind that this and future Windows Server Insider builds now have the Windows Server 2025 branding.

This appears to be a minor update as the change log is nearly identical to the one that was posted for the last preview build 26212, The one change is a new known bug that states some users may encounter boot issus with creating secure-boot Gen 2 VMs. Here is the full change log:

What's New

[NEW] Delegated Managed Service Accounts (dMSA)

A new account type known as delegated Managed Service Account (dMSA) is now available that allows migration from a traditional service account to a machine account with managed and fully randomized keys, while disabling original service account passwords. Authentication for dMSA is linked to the device identity, which means that only specified machine identities mapped in AD can access the account. Using dMSA helps to prevent harvesting credentials using a compromised account (kerberoasting), which is a common issue with traditional service accounts.

To learn more about dMSA, visit https://learn.microsoft.com/en-us/windows-server/security/delegated-managed-service-accounts/delegat....

More Server Message Block (SMB) protocol changes.

Starting with Build 26097 and higher, we are introducing the following Server Message Block (SMB) protocol changes for QUIC, signing, and encryption:

SMB over QUIC client and server disable: Administrators can now disable the SMB over QUIC client and SMB over QUIC server options with Group Policy and PowerShell.

SMB over QUIC client and server connection auditing: Successful SMB over QUIC client and SMB over QUIC server connection events are now written to the event log to include the QUIC transport.

SMB signing and encryption auditing: Administrators can now enable auditing of the SMB server and client for support of SMB signing and encryption. This shows if a third-party client or server doesn’t support SMB encryption or signing. You can configure these settings with PowerShell and Group Policy.

Windows Server Flighting is here!!

If you signed up for Server Flighting, you should receive this new build automatically later today. For more information, see Welcome to Windows Insider flighting on Windows Server - Microsoft Community Hub

The new Feedback Hub app is now available for Server Desktop users!

The app should automatically update with the latest version, but if it does not, simply Check for updates in the app’s settings tab.

windows server

Known Issues

[NEW] Secure-boot Gen2 VMs created using ISO media may not boot: Some users may encounter boot issues when creating secure-boot Gen 2 VMs. Disabling secure-boot allows the Gen2 VM to boot successfully. This will be addressed in a future release.

Upgrade does not complete: Some users may experience an issue when upgrading where the download process does not progress beyond 0%. If you encounter this issue, please upgrade to this newer build using the ISO media download option. Download Windows Server Insider Preview (microsoft.com)

Access denied error when using Diskpart --> Clean Image on Winpe.vhdx VMs created using WinPE: Create bootable media | Microsoft Learn. We are working to resolve this issue and expect to have it fixed in the next preview release.

Download Windows Server Insider Preview (microsoft.com)

Flighting: The label for this flight may incorrectly reference Windows 11. However, when selected, the package installed is the Windows Server update. Please ignore the label and proceed with installing your flight. This issue will be addressed in a future release.

windows server

Setup: Some users may experience overlapping rectangle voids following mouse clicks during "OOBE" setup. This is a graphics rendering issue and will not prevent setup from completing. This issue will be addressed in a future release.

WinPE - Powershell Scripts: Applying the WinPE-Powershell optional component does not properly install Powershell in WinPE. As a result, Powershell cmdlets will fail. Customers who are dependent on Powershell in WinPE should not use this build.

If you are validating upgrades from Windows Server 2019 or 2022, we do not recommend that you use this build as intermittent upgrade failures have been identified for this build.

This build has an issue where archiving eventlogs with "wevetutil al" command causes the Windows Event Log service to crash, and the archive operation to fail. The service must be restarted by executing "Start-Service EventLog" from an administrative command line prompt.

If you have Secure Launch/DRTM code path enabled, we do not recommend that you install this build.

Available Downloads
Downloads to certain countries may not be available. See Microsoft suspends new sales in Russia - Microsoft On the Issues

Windows Server Long-Term Servicing Channel Preview in ISO format in 18 languages, and in VHDX format in English only.

Windows Server Datacenter Azure Edition Preview in ISO and VHDX format, English only.

Microsoft Server Languages and Optional Features Preview

Keys: Keys are valid for preview builds only

  • Server Standard: MFY9F-XBN2F-TYFMP-CCV49-RMYVH
  • Datacenter: 2KNJJ-33Y9H-2GXGX-KMQWH-G6H67
  • Azure Edition does not accept a key

Symbols: available on the public symbol server – see Using the Microsoft Symbol Server.

Expiration: This Windows Server Preview will expire September 15, 2024.

You can download the new Windows Server preview from Microsoft's site and check out the full blog post here.

Report a problem with article
Seagate Game Drive for PS5 External HDD
Next Article

2TB Seagate Game Drive for PS5 External HDD with blue LED is available at its lowest price

Redfall screenshot
Previous Article

Arkane Austin delivers Redfall final update with offline mode, new skill tree, and more

Join the conversation!

Login or Sign Up to read and post a comment.

2 Comments - Add comment