Error 0xc0430001 is one of the most disruptive Windows failures you can encounter — because it happens before Windows loads. The screen goes black or blue, shows one of these messages, and the PC stops completely:
“The operating system couldn’t be loaded because Code Integrity failed to initialize. Error code: 0xc0430001”
“The operating system cannot be loaded because winload.efi is missing or corrupted. Error code: 0xc0430001”
No login screen. No recovery options from within Windows. Just a dead machine.
In June 2026, this error surged across enterprise environments when the KB5094126 Patch Tuesday update introduced new Secure Boot certificate handling that conflicted with older firmware on HP EliteBook, HP ProBook, HP Engage One Pro, and Dell Precision hardware. Community reports and IT forums flooded with accounts of PCs that booted fine on June 8 and would not start at all on June 10.
This guide explains every cause of 0xc0430001, how to get back into Windows when you cannot boot, and every fix in order.
What Does 0xc0430001 Mean?
Error 0xc0430001 means Code Integrity — the Windows boot-level security component that verifies the digital signatures of boot files and kernel drivers — failed to initialize during the startup sequence.
Code Integrity runs before Windows fully loads. It checks that bootloader files, kernel files, and critical drivers are properly signed and unmodified. If any of these checks fail — because a file is missing, corrupted, or signed with an expired or untrusted certificate — Code Integrity halts the boot process to prevent an untrusted operating system from loading.
The error is not a hardware failure and it does not mean your files are lost. It means the boot security chain cannot verify the integrity of the startup environment.
The June 2026 KB5094126 Story — Why This Error Spiked
The biggest surge of 0xc0430001 reports in 2026 traces directly to the June 9, 2026 Patch Tuesday update KB5094126.
One of the most severe bugs associated with KB5094126 is an immediate boot failure accompanied by error code 0xc0430001. System administrators tracking the bug noted a strong pattern, with the failure heavily concentrated on enterprise-grade hardware — HP EliteBook 840 G10, HP ProBook 460 G11, HP Engage One Pro, and select Dell Precision laptops.
The root cause is a compound problem. KB5094126 enabled a Secure Boot certificate update for most supported PCs — rotating the Secure Boot certificates from an older batch set to expire in June 2026 to a newer set. On most hardware, this update installed correctly. On PCs with older firmware that did not support the new certificate handling, or on PCs with small legacy 100MB EFI System Partitions that did not have enough space to write the new boot components, the update failed.
When the update failed mid-way through writing new Secure Boot components, the boot environment was left in an inconsistent state. Secure Boot detected the inconsistency and blocked Windows from loading — producing 0xc0430001.
Event Viewer on affected PCs that managed to boot showed dozens of TPM-WMI errors, with one specifically reading: “The secure boot update failed to update Boot Manager (2023) due to the error: insufficient disk space.”
This is the same EFI partition space problem that drives the 0x800f0922 error — but with a more severe consequence. Where 0x800f0922 produces a Windows Update installation failure with rollback, a failed Secure Boot certificate write can leave the EFI partition in a state that prevents booting entirely.
Three Scenarios That Produce 0xc0430001
Scenario 1 — June 2026 KB5094126 Update (Most Common Current Cause)
Affects HP EliteBook 840 G10, HP ProBook 460 G11, HP Engage One Pro, and Dell Precision laptops. The June 2026 Patch Tuesday update’s Secure Boot certificate rotation conflicted with older firmware or ran out of EFI partition space mid-write.
Scenario 2 — Enterprise Task Sequence Deployment
Affects IT administrators deploying Windows via SCCM, Intune, or other task sequence tools. After applying device drivers during deployment, the PC reboots and shows 0xc0430001 because winload.efi is missing or corrupted. This is typically caused by missing USB, SSD, chipset, or storage drivers in the WinPE boot image.
One confirmed pattern from February 2026: a new batch of Dell Pro Plus 16 (PB16250) hardware started producing 0xc0430001 during task sequences that had worked fine on the same model for months. The new hardware revision had different storage controller requirements not covered by the existing boot image driver pack.
Scenario 3 — General Code Integrity Failure
Affects any Windows PC — HP, Dell, or other brands. Causes include:
Corrupted boot configuration data (BCD) from a failed update, unexpected shutdown during update, or disk errors.
Missing boot.stl file — as noted in our KB5043080 servicing stack guide, Microsoft explicitly warns that when Dynamic Updates are applied to installation media, boot.stl must be present or devices may fail to start with error 0xc0430001.
Driver signature enforcement failure — an unsigned or improperly signed driver was loaded during a previous session and left the Code Integrity state inconsistent.
Malware or rootkit interference — malicious software that modifies boot files or driver signatures.
Before You Start — Check for BitLocker
Before attempting any fix, check whether BitLocker drive encryption is enabled on the affected PC.
If BitLocker is enabled and the boot environment has changed — which is exactly what happens when a Secure Boot certificate update fails mid-write — Windows will require your 48-digit BitLocker recovery key before you can access the drive from WinRE.
Locate your BitLocker recovery key now — before proceeding with any fix that requires accessing WinRE or the command prompt. Recovery keys are stored in:
Your Microsoft account at account.microsoft.com/devices/recoverykey.
Active Directory or Azure Active Directory for enterprise-managed devices.
A printed or saved copy you created when BitLocker was set up.
Have the key ready before attempting Fix 2 or Fix 3.
How to Boot Into Windows Recovery Environment (WinRE)
Since the error appears before Windows loads, you cannot reach recovery options from within Windows. You need to trigger WinRE externally.
Method 1 — Force WinRE via Repeated Power Interruptions
Hold the power button for 10 seconds to force shutdown. Press power to start the PC. When you see the manufacturer logo or the Windows loading spinner, hold power for 10 seconds again to interrupt. Repeat this three times. On the third or fourth boot attempt, Windows automatically enters the Recovery Environment.
Once in WinRE, select Troubleshoot, then Advanced Options to access repair tools.
Method 2 — Boot From Windows Installation Media
If Method 1 does not work, create a Windows 11 bootable USB on another PC using the Windows Media Creation Tool. Boot the affected PC from the USB by pressing the boot menu key during startup — usually F12, F10, or Esc depending on manufacturer. Select Repair your computer from the Windows setup screen to access WinRE.
Every Fix — In Order
Fix 1 — Startup Repair (Try This First)
Once in WinRE, go to Troubleshoot, Advanced Options, Startup Repair. Windows will scan for boot configuration errors and attempt to repair them automatically.
Startup Repair addresses the most common boot configuration failures — corrupted BCD entries, missing boot files, and inconsistent boot state. It is the correct first step for all three scenarios.
If Startup Repair completes successfully and the PC boots normally, proceed to Fix 4 to address the underlying cause and prevent recurrence.
Fix 2 — Uninstall KB5094126 From WinRE (June 2026 Scenario)
For the June 2026 KB5094126-triggered cases, uninstalling the update from WinRE is the most direct fix.
In WinRE, go to Troubleshoot, Advanced Options, Uninstall Updates. Select Uninstall Latest Quality Update. This removes KB5094126 and restores the boot environment to its pre-June 9 state.
Removing the offending update restores the previous working boot state. This is the fix that clears the June 2026 0xc0430001 wave.
After the PC boots successfully, go to Settings, Windows Update, and pause updates for at least 2 to 3 weeks. Then apply Fix 4 (EFI partition cleanup) and Fix 5 (firmware update) before re-enabling updates. The next cumulative update that ships after KB5094126 may resolve the Secure Boot certificate conflict — but do not re-enable updates until the EFI partition has adequate free space.
If BitLocker is enabled:
If the PC shows a BitLocker recovery screen after entering WinRE, enter your 48-digit recovery key. Then proceed with the Uninstall Update option above.
Fix 3 — Rebuild Boot Configuration Data (BCD)
For Scenario 3 general Code Integrity failures not caused by KB5094126, rebuilding the BCD resolves corrupted boot entries.
In WinRE, go to Troubleshoot, Advanced Options, Command Prompt. Run these commands in sequence:
cmd
bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcdWhen bootrec /rebuildbcd asks whether to add the Windows installation to the boot list, type Y and press Enter.
Restart and check whether the PC boots normally.
If bootrec /fixboot returns “Access is denied,” run this first:
cmd
bcdedit /export C:\BCD_Backup
attrib C:\Boot\BCD -h -r -s
ren C:\Boot\BCD BCD.old
bootrec /rebuildbcdFix 4 — Clear EFI Partition Space
For cases triggered by EFI partition space shortage — where the Secure Boot certificate update could not complete — clearing space from the EFI partition addresses the root cause.
In WinRE Command Prompt:
cmd
mountvol S: /S
del /f /s /q S:\EFI\Microsoft\Boot\Fonts\*.*
mountvol S: /DThis removes unused font files from the EFI partition — the same fix that resolves 0x800f0922. These fonts are only needed during initial Windows setup and are never accessed after Windows is installed.
After clearing the fonts, restart and allow Windows to boot. If it boots successfully, go to Windows Update and allow the Secure Boot certificate update to retry — it should now have enough space to complete.
Fix 5 — Update BIOS/Firmware
For HP and Dell enterprise hardware, updating the BIOS and firmware is a critical step for preventing 0xc0430001 recurrence after the June 2026 update.
If it gets you back to Windows, update your firmware so it does not recur.
Once the PC is booting again after Fix 2 or Fix 3:
For HP devices: go to HP Support, enter your device model, and download the latest BIOS and firmware update for your specific model. Run the firmware update from within Windows.
For Dell devices: use Dell Update or visit Dell’s support page, enter your service tag, and download all available firmware and BIOS updates.
Updated firmware has better support for the Secure Boot certificate handling that KB5094126 introduced. After updating firmware, re-enable Windows Update and allow the June 2026 update or any subsequent update to install.
Fix 6 — SFC and DISM From WinRE (Offline)
For Scenario 3 general Code Integrity failures, running system file repair from WinRE addresses corrupted boot and system files.
In WinRE Command Prompt, first identify your Windows drive letter — it may not be C: in the recovery environment:
cmd
dir C:\Windows
dir D:\WindowsUse whichever drive letter shows the Windows folder. Then run:
cmd
sfc /scannow /offbootdir=C:\ /offwindir=C:\WindowsThen run DISM offline repair:
cmd
DISM /Image:C:\ /Cleanup-Image /RestoreHealthRestart after both commands complete.
Fix 7 — In-Place Repair Upgrade
If Startup Repair, BCD rebuild, and SFC/DISM offline repair have all failed to restore booting, the in-place repair upgrade rebuilds the entire Windows boot environment while preserving files and applications.
Boot from the Windows 11 installation USB. Instead of choosing Install now, select Repair your computer, then Troubleshoot, then recover using a drive or reset this PC keeping files. Alternatively, if the PC can boot from USB to the Windows setup screen, select Repair your computer to access the full repair options.
No personal files, applications, or settings are lost in the in-place repair. Even the in-place upgrade repair install keeps your files, apps and settings.
Fix 8 — Enterprise Task Sequence Fix (SCCM/Intune Only)
For IT administrators hitting 0xc0430001 during SCCM or Intune deployment task sequences:
The error at the “Apply Device Drivers” step suggests the driver pack is missing some key drivers — USB, SSD, chipset, or storage controllers.
Add missing storage and network drivers to the WinPE boot image. Create a new boot image after adding the drivers. Update the ADK if it is not current — the February 2026 Dell Pro Plus 16 case was resolved after updating to ADK 10.1.26100.2454 and adding the correct storage drivers.
If drivers are already present, verify the boot.stl file is included in the installation media — as documented in Microsoft’s guidance for servicing stack updates including KB5043080.
Full Fix Decision Table
| Situation | Primary Fix |
|---|---|
| After KB5094126 June 2026 — HP/Dell enterprise | Fix 2 — Uninstall KB5094126 from WinRE |
| Followed by EFI partition error in Event Viewer | Fix 4 — Clear EFI fonts |
| General boot failure, no recent updates | Fix 1 — Startup Repair |
| BCD corrupted | Fix 3 — Rebuild BCD |
| Corrupted system files | Fix 6 — SFC/DISM offline |
| All boot fixes failed | Fix 7 — In-place repair |
| SCCM/Intune task sequence deployment | Fix 8 — Add missing drivers |
| BitLocker locked | Enter recovery key before any WinRE fix |
Frequently Asked Questions
What is error 0xc0430001?
Error 0xc0430001 means “Code Integrity failed to initialize” — Windows cannot verify the digital signatures of its boot files or kernel drivers during startup and halts before loading. It is a boot-level failure that prevents Windows from starting. Causes include Secure Boot certificate conflicts from Windows updates, corrupted boot configuration data, missing winload.efi, or malware that modifies boot files.
Why did 0xc0430001 appear after installing KB5094126?
The June 9, 2026 Windows 11 update KB5094126 introduced new Secure Boot certificate handling. On HP EliteBook 840 G10, HP ProBook 460 G11, HP Engage One Pro, and Dell Precision laptops with older firmware or small legacy 100MB EFI System Partitions, the Secure Boot certificate update failed mid-write due to insufficient space. This left the boot environment in an inconsistent state that prevented Windows from loading.
How do I fix 0xc0430001 if Windows won’t boot?
Force the PC into WinRE by holding the power button for 10 seconds, three times in succession. This triggers automatic boot recovery mode. From WinRE, go to Troubleshoot, Advanced Options. Try Startup Repair first. If the error was triggered by KB5094126, use Uninstall Updates to remove the latest quality update.
Do I lose my files when fixing 0xc0430001?
No. Uninstalling KB5094126 from WinRE, clearing the EFI partition, updating firmware, and running SFC/DISM offline do not affect personal files. The in-place repair upgrade also keeps all files, apps, and settings. Have your BitLocker recovery key available if your drive is encrypted.
What is the boot.stl connection to 0xc0430001?
Microsoft warns in servicing stack update documentation that when Dynamic Updates are applied to Windows installation media, boot.stl must be present. If it is absent, devices may fail to start and return error 0xc0430001. This applies specifically to IT administrators building custom Windows deployment images.
Which HP and Dell models are affected by the June 2026 0xc0430001 issue?
Confirmed affected models include the HP EliteBook 840 G10, HP ProBook 460 G11, and HP Engage One Pro on the HP side, and select Dell Precision laptops on the Dell side. The Dell Pro Plus 16 (PB16250) was also confirmed affected in enterprise deployment scenarios.
How is 0xc0430001 related to 0x800f0922?
Both errors are caused by insufficient EFI System Partition space. The difference is severity. 0x800f0922 appears during Windows Update when the EFI partition lacks space to write new boot files — Windows Update fails but the PC still boots. 0xc0430001 appears when the EFI write fails mid-way through a Secure Boot certificate update, leaving the boot environment inconsistent and preventing Windows from loading entirely. The EFI font file cleanup that fixes 0x800f0922 also addresses the root space issue that contributes to 0xc0430001.
