Windows 11 Boot Loop After KB5077181: Uninstall and Pause Updates Guide

Microsoft’s February 10, 2026 cumulative for Windows 11 — KB5077181 — is leaving a sizeable subset of machines effectively unbootable: after installation many systems enter an infinite restart loop, preventing access to the desktop and, in some cases, forcing recovery consoles or full image restores. The problem surfaced within days of the Patch Tuesday roll‑out and has been widely reported across community support threads and technician logs, where users describe more than a dozen automatic reboots, blocked sign‑ins with System Event Notification Service (SENS) errors, DHCP/network disruptions, and servicing/installation error codes such as 0x800f0983 and 0x800f0991. Early field triage points to interactions between the cumulative’s servicing stack payloads, pre‑boot certificate updates, and drivers or OEM firmware as the likely root vectors; the most consistent mitigation so far is removal of KB5077181 and pausing updates until Microsoft issues a corrected package.

Background​

Microsoft published its February 2026 cumulative update for Windows 11 on Patch Tuesday (February 10, 2026). The package is delivered as a combined monthly cumulative that raises affected machines to OS build numbers 26200.7840 (25H2) and 26100.7840 (24H2). KB5077181 bundles the usual security fixes (reported to patch 58 vulnerabilities and include several actively exploited zero‑days), servicing‑stack updates (SSUs), and platform payloads intended to prepare devices for near‑term changes such as Secure Boot certificate refreshes slated for mid‑2026. Despite those security hardenings, the update has caused severe stability regressions on a nontrivial number of systems.

• Affected builds: 26100.7840 (24H2) and 26200.7840 (25H2).
• High‑impact fixes included: multiple elevation‑of‑privilege and remote code execution patches (several CVEs called out by community reporting). These security fixes remain important; the compatibility and reliability regression is the operational problem.

What users are actually seeing (symptoms)​

Core symptom: endless reboot / unavailable desktop​

The most disruptive and consistent symptom is an infinite restart loop where the machine repeatedly powers off and back on, sometimes cycling more than a dozen times, and never reaches a stable interactive desktop. In many reports, when the desktop briefly appears users are blocked from signing in because the System Event Notification Service (SENS) fails during early session initialization. When present, the SENS failure shows messages like “The System Event Notification Service service failed the sign‑in” or “a specified procedure could not be found”, indicative of a missing or incompatible exported procedure required during early service startup.

Network corruption: connected but no internet​

Another frequent pattern is link‑level connectivity (Wi‑Fi or Ethernet shows a physical connection) while the TCP/IP stack cannot obtain DHCP leases or resolve DNS, leaving devices “connected” but offline. Community troubleshooting often traces this to the DHCP Client service failing to initialize correctly or network service registration becoming corrupted after a partial or faulty servicing commit. This network disruption compounds recovery because it can cut off remote support and online repair tools.

Installation/servicing error codes​

Technicians attempting manual installs or servicing repairs frequently encounter error codes such as 0x800f0983, 0x800f0991, and occasionally 0x800f082f during uninstall or removal from offline images. These codes usually mean the component store (WinSxS) or servicing stack is in a partially committed or mismatched state where DISM and SFC cannot fully reconcile pending operations. The practical effect is that some recovery steps succeed on many machines, while others require in‑place repair or a full image restore.

Edge cases: pre‑boot failures and Secure Boot interactions​

A minority of cases have produced Stop Codes such as UNMOUNTABLE_BOOT_VOLUME or Secure Boot violations triggered by pre‑boot certificate changes bundled in the SSU/boot‑certificate portion of the cumulative. These are rarer but severe: they can render a device unable to reach WinRE without external recovery media or a host‑level image restore. The inclusion of Secure Boot certificate updates and SSUs in modern cumulatives makes these edge cases plausible and explains why outcomes vary widely across hardware and firmware versions.

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Why this update can break boot: technical analysis​

1) Servicing stack / SSU complexity​

Modern cumulative rollouts often include a Servicing Stack Update (SSU) and other pre‑OS payloads bundled into a single monthly package. SSUs modify the component store and servicing logic that Windows uses to install future packages. When an SSU or its pre‑boot components are applied and there is an existing driver, firmware, or component‑store mismatch, the servicing process can end in a partially committed state — a brittle condition that may prevent essential early services from loading correctly. The symptoms described (SENS failures, restart loops, weird servicing error codes) are classic signs of servicing stack mismatch or partial commit.

2) Pre‑boot certificate and Secure Boot interactions​

KB5077181 explicitly carries Secure Boot certificate changes intended to address certificate expirations (community reports note related certificate refresh steps ahead of certificate expirations scheduled for June 2026). Because these changes affect pre‑OS validation steps, any unexpected firmware or firmware driver behavior can surface as pre‑boot failures or Secure Boot errors on affected platforms. When pre‑boot components change, the margin for hardware/firmware incompatibility grows — especially on devices with older or vendor‑modified UEFI stacks.

3) Driver and OEM firmware incompatibilities​

The update’s payload touches early‑load drivers and services. If a third‑party driver (particularly network or storage drivers) is incompatible with a newly applied servicing component, early service initialization can fail and cause sign‑in blockers or boot loops. Community logs show that rolling back NIC drivers or restarting the DHCP Client service sometimes remedies the network symptoms, pointing toward driver/service mismatches as a major contributor.

4) Component store corruption and pending operations​

When the Windows component store (WinSxS) or the servicing stack contains pending operations or mismatched package versions, DISM and SFC can fail to reconcile them. Error codes like 0x800f0983 and 0x800f0991 are consistent with these states. In a subset of devices, SFC/DISM repairs restore function; in others, only uninstalling the cumulative prevents further boot failures.

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Verified mitigations and recovery steps​

The community and frontline support technicians have converged on a pragmatic, repeatable mitigation path. If you manage systems that received KB5077181 and you see these failures, follow the prioritized steps below. These are field‑tested tactics that have restored normal boots for many affected devices. Each step is accompanied by the core commands used in the field.

Important safety notes before you start​

• If you can sign in, take an immediate backup of critical files before attempting uninstall or repair. Pausing updates is essential after remediation to prevent re‑application.
• If BitLocker is enabled, suspend BitLocker or ensure recovery keys are accessible prior to any in‑place repair or WinRE operation.
• Some rarer cases require external recovery media or a full image restore. If you manage fleets, make sure recovery images and media are staged and accessible.

If you can sign in (desktop accessible)​

• Back up critical files.
• Open Control Panel → Programs and Features → View installed updates.
• Locate and select KB5077181 (or the update entry matching build 26200.7840 / 26100.7840) and click Uninstall. Reboot when prompted.
• After successful boot, run elevated repairs:
• DISM /Online /Cleanup‑Image /RestoreHealth
• sfc /scannow
• Pause Windows Update: Settings → Windows Update → Pause updates (to avoid immediate reinstallation).

If the desktop is unreachable (WinRE method)​

• Enter Windows Recovery Environment (WinRE) by interrupting boot three times (power off as Windows begins to start) or boot from recovery media.
• Choose Troubleshoot → Advanced options → Uninstall Updates → Uninstall latest quality update. If this UI path works, reboot and verify.
• If the UI uninstall option is unavailable or fails, open Command Prompt in WinRE and run:
• wusa /uninstall /kb:5077181 /quiet /norestart
• Reboot and verify sign‑in. Once the desktop is reachable, run DISM /RestoreHealth and sfc /scannow, then pause updates.

Network quick fixes when you retain desktop access​

• ipconfig /release && ipconfig /renew
• netsh int ip reset
• Restart the DHCP Client service
• Roll back NIC drivers via Device Manager if network services remain unstable
  These steps have been used as quick follow‑ups for network corruption cases after uninstalling the KB.

When uninstall fails or servicing remains broken​

If the system is in a partially committed servicing state that prevents clean uninstall or continuing servicing, field technicians report the following escalations:

• Attempt SFC and DISM repair cycles (sometimes repeated after reboots).
• If that fails, perform an in‑place repair upgrade (also called a repair install) using matching build media; this can rehydrate the component store without wiping user data, but it requires free disk space and BitLocker suspension.
• As a last resort, restore from a system image or reinstall the OS — ensure backups are available first.

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Enterprise and managed‑IT guidance​

For IT teams and system administrators the KB5077181 incident is a textbook case for conservative deployment practices and pilot rings.

• Immediately move KB5077181 to a pilot ring if you have not broadly deployed it. Validate the update on representative hardware combinations (consumer OEMs, business SKUs, diverse NIC/storage drivers, and mixed firmware versions) before achieving wider deployment.
• If you already see widespread impact, coordinate with OEM partners and Microsoft support; save logs (CBS, DISM, Setupact logs) and attach them to support cases. Collect BitLocker keys and recovery media for affected endpoints.
• Ensure your recovery playbook is updated: verified WinRE USB/ISO images, recovery SOPs for forced WinRE entry, automated uninstall scripts, and stepwise rollback procedures should be ready for immediate execution.
• Avoid immediate remedial updates until Microsoft releases a fix. Use update deferral (Windows Update for Business, WSUS, or other management tooling) to block the package from reaching production endpoints.

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What this says about modern cumulative packaging risk​

KB5077181 highlights a systemic tension in Windows servicing: bundling SSUs, pre‑boot certificates, and security fixes in a single monthly package reduces update churn and helps ensure devices are prepared for near‑term security milestones; but it also concentrates risk. When a single monthly cumulative modifies both pre‑OS validation and in‑OS servicing logic, incompatibilities with third‑party drivers, OEM firmware quirks, or partial commits can produce high‑impact failures that are much harder to diagnose and remediate than a single benign hotfix.
The field evidence is clear: in many cases the fastest remediation is uninstalling the cumulative and pausing updates until Microsoft certifies a corrected build. That’s uncomfortable because it postpones important security fixes — but the operational risk from bricking endpoints often outweighs the incremental risk of delaying the patch by a short interval, particularly when administrators can use targeted compensating controls (network segmentation, endpoint monitoring) to mitigate exposure.

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Strengths and weaknesses of Microsoft’s handling so far​

Notable strengths​

• The update includes important security hardenings and fixes that target actively exploited vulnerabilities; patching those is necessary to reduce real attack surface.
• The design goal of consolidating SSU and security fixes into a single monthly package simplifies the update pipeline for many customers in the long run.

Notable weaknesses and risks​

• At the time community reporting escalated (mid‑February 2026), Microsoft’s release notes and health dashboard did not list a public “known issues” entry acknowledging the infinite reboot situations or the SENS/DHCP patterns being reported. That delayed community trust and prolonged field troubleshooting.
• Bundling pre‑boot certificates and SSUs increases the risk that a single faulty delivery will impact devices at an early stage of boot, making them harder to recover without offline media or manual intervention.
• The update surfaced on a wide range of hardware combinations, which suggests that regression testing across diverse vendor firmware and older drivers was insufficient to catch the broader compatibility surface. This is a longstanding industry problem but one that modern cumulatives amplify.

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Practical recommendations (what to do now)​

• If you manage a few machines: check for KB5077181 in the installed updates list and do not install it until you have a recovery plan. If already installed and you see symptoms, follow the uninstall steps above and pause updates.
• If you manage fleets: place the KB into a pilot ring and run compatibility tests across all OEM/driver/firmware permutations you support. Ensure BitLocker keys and recovery media are accessible, and stage toolsets (WinRE USBs, in‑place repair images).
• For affected machines you can currently sign into, uninstall via Control Panel → Programs and Features → View installed updates and pause updates immediately afterward. Then run DISM /Online /Cleanup‑Image /RestoreHealth followed by sfc /scannow.
• For machines in infinite reboot or WinRE only: open WinRE → Troubleshoot → Advanced options → Uninstall Updates, or use the WinRE command: wusa /uninstall /kb:5077181 /quiet /norestart. Reboot and verify. If that fails, escalate to repair install or image restore.

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What remains unverified and what to watch for​

A number of causal links remain plausible but not fully proven in the wild. Community telemetry strongly implicates SSU/certificate changes and driver/firmware incompatibilities, but there is not yet a conclusive, Microsoft‑published root cause analysis (as of mid‑February 2026) that ties the reboot loop to a single component. That means administrators should treat causal claims with measured skepticism and focus on the empirically‑validated mitigations (uninstall + pause updates) until an authoritative patch and postmortem are published. If Microsoft releases a patch or advisory, revalidate the fix against representative hardware before broad re‑deployment.

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Conclusion​

KB5077181 is a stark reminder that cumulative servicing complexity — particularly when SSUs and pre‑boot certificate changes are involved — magnifies the operational cost of a single failed update. The security fixes in KB5077181 are real and necessary, but the real‑world outcome for many users has been catastrophic: machines rendered unavailable, locked out of sessions by SENS failures, or caught in endless reboot cycles. The fastest, most reliable field mitigation has been to uninstall the update and pause further installations while awaiting a corrected cumulative from Microsoft. For administrators the defensive playbook is clear: treat this roll‑out as a case study in conservative deployment, pilot testing, and recovery preparedness. If you are affected, follow the documented uninstall paths, prioritize backups and BitLocker key access, and stage recovery media — and, crucially, do not assume the next cumulative will be problem‑free without validating it first.

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Source: Cyber Press https://cyberpress.org/microsoft-windows-11-kb5077181/

 

[ChatGPT]

Microsoft’s February 10, 2026 cumulative for Windows 11 — distributed as KB5077181 — is at the center of a wave of user reports describing machines that refuse to reach a usable desktop, falling into endless restart loops or blocking interactive sign‑in with service start errors and network failures.

Background / Overview​

Microsoft shipped the February 2026 monthly cumulative update for Windows 11 on February 10, 2026 as part of its normal Patch Tuesday cadence. The update is delivered as a combined package that includes the monthly security fixes, a servicing‑stack update (SSU), and ancillary platform payloads intended to keep devices current with upcoming platform hardenings. Community telemetry and forum reports began coalescing within days, describing a repeatable set of early‑boot and networking regressions affecting a subset of devices.
The problem set affects both 24H2 and 25H2 devices upgraded to the post‑update OS builds, and in some community reports the update raises OS builds to 26100.7840 (24H2) and 26200.7840 (25H2). The update package’s inclusion of SSUs and pre‑boot components appears to be a contributing factor to how an otherwise routine cumulative can create a severe operational impact.

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What users are seeing: symptoms and patterns​

Restart loops and failed sign‑ins​

The most disruptive failure mode reported is an infinite boot loop: machines repeatedly reboot — sometimes more than a dozen cycles — without ever presenting a stable desktop. In many cases where the login screen briefly appears, Windows blocks sign‑in with messages referencing the System Event Notification Service (SENS) or generic “service failed to start” errors, indicating that essential early session services cannot initialize.

Network stack corruption and DHCP problems​

Other common reports describe network connectivity collapsing after the update: devices show “connected but no internet,” experience DHCP lease failures, or lose network access altogether. These networking symptoms complicate recovery because many repair steps rely on online guidance, telemetery, or remote management services.

Servicing errors and installation failures​

Technicians have observed servicing errors where the update fails to commit cleanly, leaving the OS in a partially updated state. That scenario makes automatic recovery unreliable and increases the chance the device will reapply the faulty components on reboot.

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Why this update is different — a short technical diagnosis​

Cumulative updates today commonly bundle multiple payload types: security fixes, SSUs, and sometimes preboot or certificate updates required for Secure Boot and other platform features. When a cumulative contains a servicing‑stack or preboot component, a failure during its install can affect the very components that manage startup and early service initialization — amplifying the severity of an otherwise straightforward security fix. Community analysis points toward such a composition in KB5077181 as a plausible mechanism for the boot and SENS failures being observed.
Multiple reports cite SENS startup failures with error text like “The System Event Notification Service service failed to sign in” or “specified procedure could not be found,” which typically indicates a missing or incompatible exported procedure or binary during post‑install service startup. That failure mode explains why interactive logon can be blocked even if the kernel and drivers successfully boot.

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Immediate, practical fixes (home users and small shops)​

If you or a user machine experienced these symptoms after installing KB5077181, experienced community responders and technical writeups point to the same pragmatic mitigations: remove the problematic cumulative and stop automatic reinstallation while a corrected patch is published. Follow these steps carefully, and always ensure you have backups and recovery keys available before you make changes.

Uninstall KB5077181 from a working desktop​

• Open Control Panel.
• Select Programs and Features.
• Click View installed updates.
• Find and select KB5077181.
• Choose Uninstall, then restart the computer.
• After reboot, pause Windows Update to prevent automatic reinstallation.

This is the most straightforward route when the desktop is reachable and interactive sign‑in works.

If the desktop is unreachable — use Windows Recovery Environment (WinRE)​

• Boot into WinRE (if the machine is stuck in a reboot cycle you may be able to get WinRE automatically after several failed boots; otherwise use recovery media).
• Navigate to Troubleshoot > Advanced options > Uninstall Updates > Uninstall latest quality update.
• Alternatively, open Command Prompt from Advanced Options and run:
• wusa /uninstall /kb:5077181 /quiet /norestart
  This will queue an uninstall for the specified KB. After the command completes, manually restart the machine.

Repair the component store and system files​

Once you have a working desktop, it’s prudent to validate the component store and system integrity:

• Open an elevated Command Prompt and run:
• DISM /Online /Cleanup‑Image /RestoreHealth
• sfc /scannow
  These commands repair Windows Update component corruption and verify core system binaries.

Networking triage if you regain access but networking is unstable​

• ipconfig /release && ipconfig /renew
• netsh int ip reset
• Restart the DHCP Client service
• In Device Manager, consider rolling back NIC drivers if the network adapter shows recent changes
  These steps help when the network stack was altered or services fail to start after the update.

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Enterprise guidance: how IT teams should respond​

For organizations managing dozens to thousands of endpoints, a measured, policy‑driven process is essential. Community best practices emerging from the field include:

• Immediately move KB5077181 into a controlled pilot ring and block or defer installation on the broader estate using your management tooling (Windows Update for Business, Microsoft Intune, WSUS, Configuration Manager).
• Ensure recovery assets are current: secure BitLocker recovery keys, keep offline recovery media, and confirm that helpdesk staff have documented recovery playbooks. Several community posts warned that untested or incomplete recovery procedures can complicate restores.
• Collect logs from affected endpoints before mass remediation: CBS logs, DISM logs, Event Logs keyed to SENS, and Windows Update servicing logs. Those artifacts are vital when coordinating with OEMs or Microsoft for root cause analysis.
• Coordinate with OEM hardware vendors if network or NIC driver regressions appear to be hardware‑specific; driver rollbacks or vendor patches may be necessary.

If you run a patch cadence or quality gate, treat KB5077181 as a cautionary example: always stage cumulatives that include SSUs or preboot elements in a pilot environment before broad deployment.

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The tradeoffs and risks of uninstalling a security update​

Uninstalling a cumulative to restore availability is a valid emergency mitigation, but it carries tradeoffs:

• Removing KB5077181 will roll back security fixes included in that cumulative. That increases exposure to vulnerabilities that Microsoft intended to remediate. Balance the security risk against the operational risk of an unusable machine.
• On BitLocker‑protected systems, changing update state and boot configuration can trigger recovery prompts. Be prepared with recovery keys before initiating WinRE procedures.
• Automatic reinstallation is likely unless Windows Update is paused or blocked by management tooling; remember to pause updates after remediation to avoid reapplying the problematic package before a patched release is available.

If you manage critical infrastructure, consider compensating controls (network segmentation, temporary firewall rules, and elevated monitoring) while you await a secure, tested fix from Microsoft.

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Root cause possibilities — what to look for in logs​

Based on the community’s shared telemetry and the error text reported by affected devices, investigators should look for the following patterns in logs:

• Event Log entries showing SENS startup failures or “specified procedure could not be found” errors. Those messages implicate missing or incompatible exported procedures from DLLs that services rely on.
• Servicing and CBS logs that record a failed commit or rollback sequence during the KB installation. These logs will reveal whether the SSU or a preboot payload failed to register correctly.
• NIC driver and network service errors that coincide with the update timestamp—indicating possible driver incompatibilities introduced by the cumulative.

Collecting those logs before you rebuild or reimage will aid root cause attribution and provide necessary evidence if you escalate to Microsoft Support or OEM support channels.

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Step‑by‑step recovery checklist (concise)​

• Confirm symptoms (restart loops, SENS errors, network loss).
• Attempt uninstall from desktop: Control Panel → Programs and Features → View installed updates → Uninstall KB5077181; restart.
• If desktop unreachable, boot WinRE → Troubleshoot → Advanced options → Uninstall Updates or run: wusa /uninstall /kb:5077181 /quiet /norestart from WinRE Command Prompt.
• After regain of desktop: run DISM /Online /Cleanup‑Image /RestoreHealth and sfc /scannow.
• Pause Windows Update or target the device with update deferral policies.
• If network problems persist: ipconfig /release && ipconfig /renew, netsh int ip reset, restart DHCP Client, consider NIC driver rollbacks.

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What Microsoft’s normal patch cadence means for this situation​

Microsoft issues monthly cumulative security updates on Patch Tuesday and distributes them through Windows Update, Windows Update for Business, Microsoft Intune, Configuration Manager, WSUS, and the Microsoft Update Catalog. When a problematic cumulative is identified in the field, the company typically investigates and issues either an out‑of‑band fix or a corrected monthly cumulative at the next Patch Tuesday, depending on severity and exploitability. In the interim, the practical mitigation is uninstall + pause, accompanied by careful logging and escalation through official support channels for affected organizations.

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Long‑term remediation and monitoring​

• Reapply updates only after Microsoft publishes confirmation that KB5077181 has been fixed or superseded by a corrected package. Monitor your vendor channels and the Microsoft support communications appropriate for your environment.
• For enterprise fleets, validate the fixed update in a pilot ring that mirrors your production topologies (including devices with different NICs and firmware levels). Avoid immediate broad rollouts until pilot feedback is clean.
• Update and rehearse your recovery runbooks so helpdesk teams can respond to similar early‑boot regressions quickly. Ensure BitLocker keys and recovery media are accessible during incidents.

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Critical analysis — what this incident exposes about modern Windows servicing​

This episode underlines two enduring realities of modern OS servicing:

• Bundling complexity increases blast radius. When a cumulative includes SSUs or preboot elements, a failure during installation can affect the components responsible for startup and servicing itself, magnifying the operational impact. That means testing in diverse hardware and driver ecosystems is more important than ever.
• Operational readiness matters more than ever. Organizations that lack documented recovery procedures, accessible BitLocker keys, or staged deployment rings are more vulnerable to update‑related outages. The community’s consistent recommendation to stage updates and keep recovery assets handy is not theoretical — it’s practical incident mitigation.

Strengths of Microsoft’s model remain the regular cadence and central management options (Intune, WSUS, etc.), but this incident highlights the tension between rapid security deployment and the nontrivial risk of shipping complex cumulatives without sufficiently broad field validation.

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Final recommendations — a short list to act on today​

• If you’re an affected user: back up data if possible, uninstall KB5077181 using the steps above, pause Windows Update, and run DISM+sfc once the device is stable.
• If you’re a system administrator: immediately pause KB5077181 in your update rings, gather logs from any affected machines, and prepare recovery assets and communication templates for end users.
• If you’re responsible for fleet security: treat this as a reminder to validate cumulatives that include SSUs or preboot components in pilot rings that represent your most common hardware and driver configurations.

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This incident is a reminder that even routine monthly security updates can have disproportionate operational consequences when they touch servicing and pre‑boot components. KB5077181’s field impact is the kind of event that favors conservative rollout policies, rigorous recovery preparations, and quick, measured remediation — uninstall and pause followed by thorough log collection and staged redeployment once Microsoft confirms a fix. If you are currently troubleshooting a machine, follow the step‑by‑step checklist above, secure your BitLocker keys, and escalate to official support if the basic recovery measures fail.

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Source: The Columbus Dispatch Windows 11 users report issues after Feb. 2026 update. How to fix error