Windows 11 KB5077181 Boot Loop Data Recovery
The February 10, 2026 cumulative update KB5077181 for Windows 11 24H2 and 25H2 is causing infinite boot loops. Systems cycle through 15 or more restarts before failing with a KERNEL_SECURITY_CHECK_FAILURE blue screen or an UNMOUNTABLE_BOOT_VOLUME error. The update injects new Secure Boot certificates that alter TPM measurements, triggering BitLocker lockouts on encrypted systems.
Most systems can be fixed for free using the Windows Recovery Environment. This page walks you through the DIY fix first. If that fails because the boot loop already corrupted your NTFS file system or triggered a BitLocker lockout without a recovery key, we recover the data. Call (512) 212-9111 for a free evaluation. No data, no fee.
What KB5077181 Does to Your System
KB5077181 is a Patch Tuesday cumulative update released February 10, 2026. It targets Windows 11 version 24H2 (OS Build 26100.7840) and version 25H2 (OS Build 26200.7840). The update carries a critical payload: it replaces expiring 2011 Secure Boot certificates with 2023 certificates in the UEFI signature database. This certificate rotation is necessary for long-term platform security, but the implementation interacts badly with certain firmware and hardware configurations.
When the servicing stack applies the Secure Boot certificate injection, it modifies bootmgfw.efi and the Secure Boot database variables stored in NVRAM. These changes alter the Platform Configuration Register 7 (PCR 7) values that the TPM measures during every boot. On systems where the firmware cannot process the AMI certificate update gracefully, the boot chain breaks. The TPM detects that PCR 7 no longer matches the expected measurements, assumes the system has been tampered with, and either halts boot entirely or demands a BitLocker recovery key.
Windows then reboots automatically. The same certificate injection fails again. The system reboots again. This cycle continues for 15 or more iterations. Community reports document systems that looped for over an hour before finally throwing an UNMOUNTABLE_BOOT_VOLUME stop error or dropping into the Windows Recovery Environment.
Hardware Configurations That Fail
ASRock + AMD fTPM
ASRock motherboards with AMD firmware TPM modules halt at a UEFI "Update Y/N" prompt during the Secure Boot certificate injection. The AMI firmware cannot process the certificate update unattended. The system stalls until the user physically responds to the prompt, but on headless or remote systems this creates a permanent hang followed by watchdog-triggered reboots.
Samsung Galaxy Book
Samsung Galaxy Book 4 and Galaxy Desktop systems throw "C:\ is not accessible - Access denied" after the update. The root cause is orphaned Access Control Entries (ACEs) that conflict with the Samsung Galaxy Connect app. The update modifies system directory permissions in a way that collides with Samsung's pre-installed software, locking the user out of the boot volume.
Nvidia GPU Systems
Systems with Nvidia graphics cards experience black screens of death when waking from S3 sleep after the update. The crash involves dxgmms2.sys (DirectX Graphics MMS) and throws KERNEL_SECURITY_CHECK_FAILURE (Bug Check 0x139). The failure occurs specifically during power state transitions, not during normal operation.
How the Boot Loop Damages Your Data
KB5077181 is a software update, not a hardware defect. The update itself does not physically damage your drive. The data damage comes from two secondary effects: NTFS corruption from repeated forced reboots, and BitLocker lockouts from changed TPM measurements.
NTFS $MFT and $LogFile Corruption
During the Component Based Servicing (CBS) phase, Windows writes to the system registry hives, the WinSxS component store, and the NTFS transactional journal ($LogFile) simultaneously. When the boot loop forces a hard power reset mid-write, the sequence of file operations recorded in $LogFile becomes desynchronized with the Master File Table ($MFT). The $MFT is the index that maps every file and directory on the NTFS volume. If the $MFT and its mirror ($MFTMirr) disagree after an interrupted write, the volume may mount as RAW or show as unallocated.
Running chkdsk /f on a volume in this state can cause further damage. Chkdsk resolves inconsistencies by deleting orphaned file records and truncating the $LogFile. On a volume where the $MFT itself is partially corrupted, this means chkdsk may delete the index entries your files depend on. If your drive shows as RAW in the Windows Recovery Environment, do not run chkdsk. Contact us for file system recovery instead.
BitLocker Lockout from Changed PCR 7 Measurements
Windows 11 enables Device Encryption silently on most OEM hardware with TPM 2.0. The encryption key is stored in the TPM and released automatically during normal boot based on PCR measurements. KB5077181 changes the Secure Boot database, which changes PCR 7. The TPM detects a mismatch and locks the volume.
The system then prompts for a 48-digit BitLocker recovery key. If you signed in with a Microsoft Account during Windows setup, check account.microsoft.com/devices/recoverykey. If the key is there, the data is recoverable. If you used a local account and never saved a recovery key, the data is encrypted with AES-XTS and cannot be decrypted by any lab. We will tell you this upfront rather than take your money and your drive. For BitLocker recovery with a known key, we unlock and image the volume as part of the recovery.
SSD Controller Stress from Repeated Power Loss
While the KB5077181 bug is software-based, forcing an SSD through dozens of sudden power-loss events (one per boot loop cycle) can trigger firmware panic in SSDs with older or degraded controllers. The flash translation layer (FTL) may fail to commit its journal entries between power cycles. If your SSD stopped appearing in BIOS after the boot loop, the issue may have escalated from a Windows update firmware problem to an SSD controller failure requiring PC-3000 SSD intervention.
DIY Fix: Uninstall KB5077181 via Windows Recovery Environment
If the boot loop has not yet corrupted your file system or triggered a BitLocker lockout, you can uninstall KB5077181 for free using the Windows Recovery Environment (WinRE). Follow these steps in order.
Enter Windows Recovery Environment
Force power off the machine three times during the Windows boot logo (hold the power button until the screen goes black). On the third forced shutdown, Windows will automatically boot into the Recovery Environment. Navigate to Troubleshoot > Advanced Options > Command Prompt.
Identify Your Windows Drive Letter
In WinRE, the boot drive is not always C:\. Run diskpart, then list volume to find the volume with your Windows installation (look for the largest NTFS partition). Note the drive letter. Type exit to leave diskpart.
Uninstall KB5077181 with WUSA
Run the following command (replace C:\ with your actual drive letter if different):
If WUSA reports that the update cannot be found or is blocked in the recovery environment, proceed to step 4.
Offline DISM Removal (If WUSA Fails)
List installed packages with DISM, then remove the KB5077181 package:
Replace <package-name-from-above> with the full package identity string from the Get-Packages output. If DISM returns error 0x800f0983 (component directory missing), the servicing stack is too corrupted to roll back. Stop here and seek professional recovery.
Rebuild Boot Configuration (If Needed)
If the system still throws UNMOUNTABLE_BOOT_VOLUME after removing the update, rebuild the boot records:
Restart and Verify
Close the Command Prompt and restart. If Windows boots normally, immediately pause Windows Update (Settings > Windows Update > Pause updates) until Microsoft releases a fixed version of KB5077181. If the system still does not boot, the file system may be corrupted beyond what the recovery environment can fix.
When the DIY Fix Fails
The WinRE uninstall method works when the NTFS file system is intact and the servicing stack can cleanly roll back the update. It does not work in these scenarios:
- ✗DISM returns error 0x800f0983. The component directory needed to roll back the update is missing or corrupted. The servicing stack cannot undo the certificate injection.
- ✗The drive shows as RAW or unallocated in diskpart. The NTFS $MFT is corrupted from repeated forced reboots during the CBS phase. The partition structure is damaged at the file system level.
- ✗BitLocker prompts for a recovery key you do not have. The PCR 7 measurements changed and the TPM locked the volume. Without the 48-digit recovery key from your Microsoft Account, the data is encrypted.
- ✗The SSD is no longer detected in BIOS. Repeated power-loss events from the boot loop stressed the SSD controller into a firmware panic state. The drive needs firmware-level recovery.
If any of these apply, the data is beyond what Windows tools can fix. Ship the drive to our Austin lab for a free evaluation. We will tell you what recovery tier applies and quote a firm price before any paid work begins.
Data Recovery Pricing
Most KB5077181 boot loop recoveries fall in the file system recovery tier ($250 for HDD or SSD) because the underlying hardware is healthy and the damage is limited to NTFS metadata corruption. If the SSD controller also failed from the reboot stress, the price moves to the firmware tier. Free evaluation. Firm quote. No data, no fee.
HDD Pricing
Simple Copy
Low complexityYour drive works, you just need the data moved off it
$100
3-5 business days
Functional drive; data transfer to new media
Rush available: +$100
File System Recovery
Low complexityYour drive isn't recognized by your computer, but it's not making unusual sounds
From $250
2-4 weeks
File system corruption. Accessible with professional recovery software but not by the OS
Starting price; final depends on complexity
Firmware Repair
Medium complexityYour drive is completely inaccessible. It may be detected but shows the wrong size or won't respond
$600–$900
3-6 weeks
Firmware corruption: ROM, modules, or translator tables corrupted; requires PC-3000 terminal access
CMR drive: $600. SMR drive: $900.
Head Swap
High complexityMost CommonYour drive is clicking, beeping, or won't spin. The internal read/write heads have failed
$1,200–$1,500
4-8 weeks
Head stack assembly failure. Transplanting heads from a matching donor drive on a clean bench
50% deposit required. CMR: $1,200-$1,500 + donor. SMR: $1,500 + donor.
50% deposit required
Surface / Platter Damage
High complexityYour drive was dropped, has visible damage, or a head crash scraped the platters
$2,000
4-8 weeks
Platter scoring or contamination. Requires platter cleaning and head swap
50% deposit required. Donor parts are consumed in the repair. Most difficult recovery type.
50% deposit required
Hardware Repair vs. Software Locks
Our "no data, no fee" policy applies to hardware recovery. We do not bill for unsuccessful physical repairs. If we replace a hard drive read/write head assembly or repair a liquid-damaged logic board to a bootable state, the hardware repair is complete and standard rates apply. If data remains inaccessible due to user-configured software locks, a forgotten passcode, or a remote wipe command, the physical repair is still billable. We cannot bypass user encryption or activation locks.
No data, no fee. Free evaluation and firm quote before any paid work. Full guarantee details. Head swap and surface damage require a 50% deposit because donor parts are consumed in the attempt.
Target drive: The destination drive we copy recovered data onto. You can supply your own or we provide one at cost. For larger capacities (8TB, 10TB, 16TB and above), target drives cost $400+ extra. All prices are plus applicable tax.
SSD Pricing (NVMe)
| Service Tier | Price | Description |
|---|---|---|
| Simple CopyLow complexity | $200 | Your NVMe drive works, you just need the data moved off it Functional drive; data transfer to new media Rush available: +$100 |
| File System RecoveryLow complexity | From $250 | Your NVMe drive isn't showing up, but it's not physically damaged File system corruption. Visible to recovery software but not to OS Starting price; final depends on complexity |
| Circuit Board RepairMedium complexity – PC-3000 required | $600–$900 | Your NVMe drive won't power on or has shorted components PCB issues: failed voltage regulators, dead PMICs, shorted capacitors May require a donor drive (additional cost) |
| Firmware RecoveryMedium complexity – PC-3000 required | $900–$1,200 | Your NVMe drive is detected but shows the wrong name, wrong size, or no data Firmware corruption: ROM, modules, or system files corrupted Price depends on extent of bad areas in NAND |
| PCB / NAND SwapHigh complexity – precision microsoldering and BGA rework50% deposit | $1,200–$1,500 | Your NVMe drive's circuit board is severely damaged and requires NAND chip transplant to a donor PCB NAND swap onto donor PCB. Precision microsoldering and BGA rework required 50% deposit required; donor drive cost additional |
Hardware Repair vs. Software Locks
Our "no data, no fee" policy applies to hardware recovery. We do not bill for unsuccessful physical repairs. If we replace a hard drive read/write head assembly or repair a liquid-damaged logic board to a bootable state, the hardware repair is complete and standard rates apply. If data remains inaccessible due to user-configured software locks, a forgotten passcode, or a remote wipe command, the physical repair is still billable. We cannot bypass user encryption or activation locks.
All tiers: Free evaluation and firm quote before any paid work. No data, no fee on all tiers (NAND swap requires a 50% deposit because donor parts are consumed in the attempt).
Target drive: The destination drive we copy recovered data onto. You can supply your own or we provide one at cost. All prices are plus applicable tax.
Data Recovery Standards & Verification
Our Austin lab operates on a transparency-first model. We use industry-standard recovery tools, including PC-3000 and DeepSpar, combined with strict environmental controls to make sure your hard drive is handled safely and properly. This approach allows us to serve clients nationwide with consistent technical standards.
Open-drive work is performed in a ULPA-filtered laminar-flow bench, validated to 0.02 µm particle count, verified using TSI P-Trak instrumentation.
Transparent History
Serving clients nationwide via mail-in service since 2008. Our lead engineer holds PC-3000 and HEX Akademia certifications for hard drive firmware repair and mechanical recovery.
Media Coverage
Our repair work has been covered by The Wall Street Journal and Business Insider, with CBC News reporting on our pricing transparency. Louis Rossmann has testified in Right to Repair hearings in multiple states and founded the Repair Preservation Group.
Aligned Incentives
Our "No Data, No Charge" policy means we assume the risk of the recovery attempt, not the client.
Technical Oversight
Louis Rossmann
Louis Rossmann's well trained staff review our lab protocols to ensure technical accuracy and honest service. Since 2008, his focus has been on clear technical communication and accurate diagnostics rather than sales-driven explanations.
We believe in proving standards rather than just stating them. We use TSI P-Trak instrumentation to verify that clean-air benchmarks are met before any drive is opened.
See our clean bench validation data and particle test videoFrequently Asked Questions
What is KB5077181 and why is it causing boot loops?
KB5077181 is a cumulative update released February 10, 2026 for Windows 11 versions 24H2 (Build 26100.7840) and 25H2 (Build 26200.7840). The update replaces expiring 2011 Secure Boot certificates with 2023 certificates in the UEFI signature database. On certain hardware configurations, this certificate injection alters the Platform Configuration Register 7 (PCR 7) measurements that the TPM uses to validate the boot chain. The TPM interprets the changed measurements as a security breach, halts the boot process, and triggers either a KERNEL_SECURITY_CHECK_FAILURE BSOD or a BitLocker recovery prompt. The system then reboots automatically and hits the same failure, creating an infinite loop.
Which systems are affected by the KB5077181 boot loop?
Three hardware configurations are most frequently reported. ASRock motherboards with AMD fTPM modules stall at UEFI prompts during the Secure Boot certificate update. Samsung Galaxy Book systems throw "C:\ is not accessible" errors due to Access Control Entry conflicts with the Samsung Galaxy Connect app. Systems with Nvidia GPUs experience black screens tied to the dxgmms2.sys driver when waking from sleep states after the update. The boot loop itself can occur on any Windows 11 24H2 or 25H2 system where the Secure Boot certificate injection fails to complete cleanly.
Can the KB5077181 boot loop trigger a BitLocker lockout?
Yes. KB5077181 modifies the Secure Boot database, which changes the PCR 7 values stored in the TPM. BitLocker uses these PCR measurements to verify the boot chain has not been tampered with. When the measurements change mid-update, the TPM refuses to release the encryption key and Windows prompts for a 48-digit recovery key. If you signed into Windows with a Microsoft Account, check account.microsoft.com/devices/recoverykey for your key. If no recovery key was saved anywhere, the data is cryptographically inaccessible. No data recovery lab can bypass AES-XTS 128/256 BitLocker encryption without the key.
Can repeated reboots from the boot loop damage my files?
Yes. During the Component Based Servicing (CBS) phase, Windows writes aggressively to the system registry and NTFS journal. Each forced reboot interrupts these writes mid-transaction. The NTFS $LogFile (transactional journal) becomes desynchronized with the Master File Table ($MFT). After enough forced reboots, the partition may appear as RAW or unallocated in recovery tools. Standard chkdsk cannot safely resolve this level of corruption without risking further data destruction. If your drive shows as RAW after the boot loop, stop rebooting and contact us for evaluation.
Sources
- 1.Microsoft Support: KB5077181 cumulative update for Windows 11 version 24H2 (OS Build 26100.7840) and version 25H2 (OS Build 26200.7840), released February 10, 2026 via Patch Tuesday.
- 2.BleepingComputer, Notebookcheck, and Windows Central reporting on KB5077181 boot loop issues, BSOD codes KERNEL_SECURITY_CHECK_FAILURE (0x139) and UNMOUNTABLE_BOOT_VOLUME, and installation failure codes 0x800f0983 and 0x800f0991.
- 3.Community reports from r/Windows11 and r/sysadmin documenting ASRock AMD fTPM UEFI prompt hangs, Samsung Galaxy Book ACE conflicts, and Nvidia dxgmms2.sys crashes following KB5077181 installation.
- 4.Microsoft documentation on Secure Boot certificate rotation from 2011 to 2023 certificates and the impact on TPM Platform Configuration Register 7 (PCR 7) measurements used for BitLocker volume protection.
- 5.Dell Support and Microsoft Learn documentation on Windows Recovery Environment (WinRE) offline DISM servicing and WUSA package removal for failed cumulative updates.
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Stuck in a boot loop after KB5077181?
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