On March 10, 2026, Microsoft released KB5079473 — the March Patch Tuesday update for Windows 11. It brought nine new features including Emoji 16, built-in Sysmon, and a Taskbar speed test. It also, quietly, broke Microsoft account sign-in across a significant number of apps.
Teams, OneDrive, Outlook, Excel, Word, Edge, and Microsoft 365 Copilot all affected users with the same frustrating error: a “no internet” message during sign-in, even when the device had a perfectly working internet connection. The irony was pointed — an update that added an internet speed test tool also broke the internet sign-in for Microsoft’s own apps.
Eleven days later, on March 21, 2026, Microsoft released KB5085516 — an emergency out-of-band update specifically designed to permanently fix the sign-in issue.
This guide explains what happened, who was affected, what KB5085516 contains, and how to install it.
What Is KB5085516?
Microsoft released an out-of-band update, KB5085516, to fix critical sign-in issues on Windows 11. The bug introduced by the March 2026 Patch Tuesday KB5079473 affected apps such as Teams, Outlook, OneDrive, Edge, Excel, Word, and Copilot.
KB5085516 is an out-of-band cumulative update for Windows 11 versions 25H2 and 24H2, released March 21, 2026. It moves affected systems to OS builds 26200.8039 on Windows 11 25H2 and 26100.8039 on Windows 11 24H2.
This out-of-band update includes all protections and improvements from the March 10, 2026 security update. In other words, KB5085516 is not just the fix for the sign-in issue — it is a cumulative package containing everything from KB5079473 plus the additional repair. A device that installs KB5085516 without having previously installed KB5079473 will receive all of March’s security and feature content alongside the sign-in fix.
Microsoft told Windows Latest that it’s an out-of-band update meant to address major issues affecting Microsoft account internet connectivity in some apps after the March 2026 Update.
What Exactly Broke — The Full Story
Understanding KB5085516 requires understanding what KB5079473 accidentally changed.
The bug broke Microsoft account sign-in in apps such as Teams, Office apps, OneDrive, and Outlook. Since the update was part of the March 2026 Patch Tuesday cycle, it installed automatically and ended up breaking Microsoft sign-in for some.
The failure mode was specific and deeply frustrating:
After you install the Windows update released on or after March 10, 2026, some users might experience an issue signing in to apps with a Microsoft account. Even when the device has a working internet connection, a “no Internet” error appears during sign in and prevents access to Microsoft services and apps such as Microsoft Teams Free and OneDrive.
The “no internet” error was a false negative — the device had internet access, and browsers worked normally. The issue was not with the network connection itself but with how the Microsoft account authentication components were communicating with Microsoft’s sign-in servers after KB5079473 changed something in the network authentication stack.
Apps confirmed affected:
Microsoft Teams Free, OneDrive, Microsoft Edge, Microsoft Excel, Microsoft Word, Microsoft Outlook, Microsoft 365 Copilot, and any other application that uses a Microsoft account for authentication.
Who was NOT affected:
Only sign-ins using Microsoft accounts are affected. Businesses using Microsoft Entra ID for app authentication will not experience this issue.
This is an important distinction for enterprise environments. Organizations using Microsoft Entra ID — formerly Azure Active Directory — for employee authentication were not affected. The issue was specific to consumer Microsoft accounts (MSA) used for personal and Teams Free sign-ins.
What KB5085516 Contains
KB5085516 is a targeted fix with a clearly defined scope.
What it includes:
All security patches and feature content from KB5079473 — the March 10, 2026 Patch Tuesday update with Emoji 16, Sysmon, the Taskbar speed test, File Explorer search improvements, and 79 vulnerability fixes including two zero-days.
The permanent fix for the Microsoft account “no internet” sign-in error.
What it does NOT include:
No new features beyond what was in KB5079473. No additional security patches beyond the March 10 content. No preview of upcoming April features.
KB5085516 is a surgical repair — it corrects the broken component and restores the full March update to its intended state.
KB5085516 vs KB5085518 — Which One Applies to You?
Microsoft released two variants of the March 21 emergency fix.
| KB5085516 | KB5085518 | |
|---|---|---|
| Applies to | All Windows 11 25H2 and 24H2 devices | Devices enrolled in Windows Autopatch Hotpatching |
| Restart required | Yes | No |
| Delivery | Optional — manual trigger required | Through hotpatch channel |
| OS Build | 26200.8039 / 26100.8039 | Different build |
For devices enrolled in Hotpatch, this issue is addressed via KB5085518, which allows receiving the update without requiring a restart.
For standard Windows 11 users — including all Home and Pro editions — KB5085516 is the correct update. KB5085518 is exclusively for Windows 11 Enterprise devices enrolled in Windows Autopatch hotpatching, which allows security updates to apply without rebooting.
Is KB5085516 Optional or Mandatory?
This emergency update shows up as “2026-03 Update (KB5085516) (26200.8039)” and it does not appear to download automatically. Microsoft confirmed it is an optional out-of-band patch, and anybody with Microsoft account internet issues in these apps can download it.
KB5085516 is optional — it does not install automatically through Windows Update. You must manually trigger it.
You should install the update if you have issues opening apps in Windows 11, but if everything appears to be stable, you do not have to install it.
This means:
Install KB5085516 if: You installed KB5079473 and are experiencing the “no internet” error when signing into Teams, OneDrive, Outlook, Office apps, or Edge with a Microsoft account.
No action needed if: You installed KB5079473 and all Microsoft account sign-ins are working correctly. The sign-in issue only affected a subset of devices — not every system that installed KB5079473 experienced the problem.
All content from KB5085516 shipped to all users automatically through the April 2026 Patch Tuesday update KB5083769 — which included KB5085516 in its fix chain. Any device that has received April or later updates already has the Microsoft account sign-in fix.
How to Check If You Need KB5085516
Before installing, verify whether the issue applies to you.
Step 1 — Check your current OS build
Go to Settings, System, About. Under Windows specifications, note your OS build number.
If your build is 26200.8039 or higher (Windows 11 25H2) or 26100.8039 or higher (Windows 11 24H2), KB5085516 is already installed — either directly or as part of a later cumulative update.
If your build is 26200.8037 or 26100.8037 — the exact builds from KB5079473 — and you are experiencing sign-in failures, KB5085516 is what you need.
Step 2 — Check for the sign-in error
Open Teams Free, OneDrive, or any Microsoft app that requires sign-in. If you see a “no internet” or network connectivity error despite having a working internet connection, you are experiencing the issue KB5085516 fixes.
Step 3 — Check Windows Update History
Go to Settings, Windows Update, Update History. Look for KB5085516 with a Successfully installed status. If it is present, the fix has already been applied.
How to Install KB5085516
If you have a computer affected by these bugs, you should install this update immediately by going to Settings, Windows Update and clicking the Check for updates button.
Method 1 — Windows Update
Go to Settings, Windows Update, Check for updates. KB5085516 appears as “2026-03 Update (KB5085516) (26200.8039)” in the optional updates section. Click Download and install. Restart when prompted.
It takes approximately five minutes to download and another five to seven minutes to finish applying the patch.
Method 2 — Microsoft Update Catalog
Download KB5085516 for the correct Windows 11 version — 25H2 or 24H2 — from the Microsoft Update Catalog. Run the downloaded package and follow the on-screen instructions.
Go to catalog.update.microsoft.com. Search for KB5085516. Select the package matching your Windows version and architecture — x64 or ARM64. Download the .MSU file. Run it and restart when complete.
If you encounter error 0x80244022 when connecting to Windows Update or the catalog, our full error fix guide covers every solution.
Prerequisite:
This update is offered through Windows Update for devices running Windows 11 that have already installed KB5079473.
KB5085516 requires KB5079473 to be installed first on most installation paths. However, since KB5085516 is itself cumulative and contains all of KB5079473’s content, installing directly from the catalog on a clean system also works.
KB5043080 — the September 2024 checkpoint SSU — must also be present as the foundational prerequisite for all Windows 11 25H2 and 24H2 updates.
What Happened If You Did Not Install KB5085516?
If you experienced the Microsoft account sign-in failure and did not install KB5085516 in March, the fix still reached your system — just through a different path.
The content of KB5085516 was carried forward into the subsequent update chain. The April 2026 Patch Tuesday KB5083769 explicitly lists KB5085516 among the updates whose content it contains. Any device that installed KB5083769 or any subsequent 2026 Windows 11 update received the Microsoft account sign-in fix as part of that cumulative package.
This out-of-band update contains quality improvements from KB5079473 released March 10, 2026, KB5085516 released March 21, 2026, and KB5079391 released March 26, 2026.
This is the nature of Windows’ cumulative update model — fixes from emergency OOB updates carry forward into all subsequent monthly updates, ensuring that devices which missed the emergency patch still receive the fix eventually.
The Workaround Microsoft Provided Before KB5085516
Between March 10 — when KB5079473 broke sign-in — and March 21 — when KB5085516 fixed it — Microsoft provided a temporary workaround for affected users.
The workaround involved signing out of the affected Microsoft account in Windows Settings and signing back in using a web browser rather than the in-app sign-in flow. This bypassed the broken authentication component and allowed users to re-authenticate successfully.
KB5085516 permanently resolves the underlying issue. Users who used the workaround do not need to do anything additional after installing KB5085516 — the sign-in behavior normalizes automatically.
The March 2026 Timeline — Four Updates in Three Weeks
The March 2026 period produced an unusual cluster of Windows 11 updates. Understanding the full timeline clarifies where KB5085516 fits.
March 10, 2026 — KB5079473 (Patch Tuesday)
KB5079473 ships as the mandatory March cumulative update. Nine new features, 79 vulnerability fixes, two zero-days patched. Also accidentally breaks Microsoft account sign-in for a subset of users.
March 21, 2026 — KB5085516 (Emergency OOB)
KB5085516 ships as an optional emergency fix for the sign-in issue. OS builds move to 26200.8039 and 26100.8039. Contains all of KB5079473’s content plus the sign-in repair.
March 26, 2026 — KB5079391 (Optional Non-Security Preview)
An optional non-security preview update with quality improvements. Subsequently pulled from distribution — listed as “no longer offered” in Microsoft’s documentation.
March 31, 2026 — KB5086672 (OOB)
A second out-of-band update that combines KB5085516’s content, KB5079391’s improvements, and a fix for an installation error that affected some devices attempting to install KB5079391. OS builds move to 26200.8117 and 26100.8117.
This is why the April 2026 update KB5083769 lists four March updates in its fix chain — all four shipped within the same calendar month.
Frequently Asked Questions
What is KB5085516?
KB5085516 is an emergency out-of-band cumulative update for Windows 11 versions 25H2 and 24H2, released March 21, 2026. It fixes a Microsoft account sign-in failure — showing a “no internet” error even with a working connection — that was introduced by the March 10, 2026 Patch Tuesday update KB5079473. It moves systems to OS builds 26200.8039 and 26100.8039.
Why did Microsoft account sign-in break after March Patch Tuesday?
The March 10, 2026 Patch Tuesday update KB5079473 made a change to Windows networking or authentication components that caused the Microsoft account sign-in flow to incorrectly report a “no internet” connectivity error. The issue only affected consumer Microsoft accounts — business accounts using Microsoft Entra ID were not affected.
Which apps were affected by the sign-in failure?
Teams Free, OneDrive, Microsoft Edge, Microsoft Excel, Microsoft Word, Microsoft Outlook, Microsoft 365 Copilot, and any other app that uses Microsoft account authentication. Apps and services using Entra ID for authentication were not affected.
Is KB5085516 mandatory?
No. KB5085516 is an optional out-of-band update that does not install automatically. You must manually trigger it through Windows Update or download it from the Microsoft Update Catalog. However, its content was included in all subsequent Windows 11 mandatory updates from April 2026 onward.
If I have the April 2026 update KB5083769, do I need KB5085516?
No. KB5083769 includes all content from KB5085516. Any device running KB5083769, KB5094126, KB5101650, or any later 2026 Windows 11 update already has the Microsoft account sign-in fix.
What is the difference between KB5085516 and KB5085518?
Both fix the same Microsoft account sign-in issue from March 2026. KB5085516 is the standard cumulative update requiring a restart for all Windows 11 25H2 and 24H2 devices. KB5085518 is the hotpatch variant for Windows 11 Enterprise devices enrolled in Windows Autopatch hotpatching — it applies without requiring a restart.
What OS builds does KB5085516 install?
KB5085516 moves Windows 11 25H2 to build 26200.8039 and Windows 11 24H2 to build 26100.8039. These are one increment above KB5079473’s builds of 26200.8037 and 26100.8037.
How long does KB5085516 take to install?
Approximately five minutes to download and five to seven minutes to apply the patch, followed by a required restart.
