HP Laptop Blue Screen of Death (BSOD): Fix Every Stop Code (0xc00021a, INACCESSIBLE_BOOT_DEVICE, KERNEL_SECURITY_CHECK_FAILURE & More)

Understanding HP Blue Screen Errors

A Blue Screen of Death (BSOD) on an HP laptop, desktop, or all-in-one occurs when Windows encounters a fatal system error it cannot recover from. The screen displays a stop code that identifies the root cause. HP devices — including the Pavilion, Envy, EliteBook, ProBook, Omen, Victus, ZBook, Stream, and Notebook lines — all share a common troubleshooting path, though specific drivers like HP's Bluetooth stack or Wi-Fi adapters introduce unique stop codes.

Common HP Stop Codes and Their Meanings

• INACCESSIBLE_BOOT_DEVICE (0x0000007B / hp stop code inaccessible boot device): Windows cannot access the boot partition. Usually caused by a corrupted NTFS filesystem, a failed SSD/HDD, a missing storage driver, or a BIOS/UEFI setting change (e.g., SATA mode switched from AHCI to IDE).
• UNMOUNTABLE_BOOT_VOLUME (0xC00021A / hp unmountable boot volume): Similar to above; the boot volume's filesystem is corrupt or the volume cannot be mounted.
• KERNEL_SECURITY_CHECK_FAILURE (0x00000139 / hp kernel security check failure): A data structure integrity check failed. Often triggered by incompatible, outdated, or corrupted drivers — especially after a Windows feature update.
• WDF_VIOLATION (0x0000010D / wdf_violation hp): A Windows Driver Framework violation, typically caused by a faulty driver using WDF incorrectly. HP's own chipset or USB drivers are common culprits.
• SYSTEM_SERVICE_EXCEPTION (hp system service exception): Usually caused by a driver attempting an illegal operation. Graphics drivers (AMD/NVIDIA/Intel) and antivirus software are frequent causes on HP machines.
• bthport.sys BSOD (bthport sys blue screen hp): The Bluetooth port driver crashes. This is a known issue on HP devices after certain Windows updates.
• rtump64x64.sys / rtux64w10.sys BSOD: Realtek network adapter drivers crashing. Common on HP Pavilion and Envy models using Realtek Wi-Fi or LAN chips.
• stop code 0xc00021a hp: A critical system process (winlogon.exe or csrss.exe) failed. Often caused by corrupted system files or a bad Windows update.

Step 1: Capture the Stop Code and Identify the Trigger

Before attempting any fix, note the exact stop code displayed on the blue screen. On Windows 10/11, the BSOD screen shows:

• A frowny face emoji
• A plain-English description (e.g., "KERNEL_SECURITY_CHECK_FAILURE")
• A stop code (e.g., 0x00000139)
• Sometimes a specific filename (e.g., bthport.sys)

If the machine reboots too quickly to read it:

1. Go to Settings > System > About > Advanced system settings > Startup and Recovery.
2. Uncheck Automatically restart under System failure.
3. After the next BSOD, the screen will stay visible.

Alternatively, read the minidump after reboot:

• Open Event Viewer > Windows Logs > System and filter for Critical errors.
• Use WinDbg or the free WhoCrashed tool to analyze C:\Windows\Minidump\*.dmp files.

Step 2: Boot into Safe Mode

If the BSOD prevents normal boot:

1. Force-shutdown the HP laptop 3 times in a row during the Windows logo to trigger Automatic Repair / WinRE.
2. In the recovery environment, go to Troubleshoot > Advanced Options > Startup Settings > Restart.
3. Press F4 for Safe Mode or F5 for Safe Mode with Networking.

On HP laptops, you can also press F11 at startup to access HP Recovery Manager, or F9 to access Boot Menu.

Step 3: Fix Corrupted System Files (SFC & DISM)

For stop codes like 0xc00021a, WDF_VIOLATION, and SYSTEM_SERVICE_EXCEPTION, corrupted Windows system files are a primary suspect. Run these commands from an elevated Command Prompt (Run as Administrator):

sfc /scannow
DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth

After DISM completes, run sfc /scannow again and restart.

Step 4: Repair the Boot Partition (INACCESSIBLE_BOOT_DEVICE / UNMOUNTABLE_BOOT_VOLUME)

Boot from a Windows 10/11 installation USB (create one with the Media Creation Tool on another PC):

1. At the setup screen, click Repair your computer > Troubleshoot > Advanced Options > Command Prompt.
2. Run the following repair commands:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd
chkdsk C: /f /r /x

For UNMOUNTABLE_BOOT_VOLUME specifically, also run:

chkdsk C: /f

If CHKDSK cannot lock the drive, schedule it for the next boot:

chkdsk C: /f /r

Step 5: Roll Back or Uninstall Problematic Drivers

For bthport.sys, rtump64x64.sys, rtux64w10.sys, and WDF_VIOLATION:

1. Boot into Safe Mode.
2. Open Device Manager (devmgmt.msc).
3. Find the offending device:
   • For bthport.sys: Bluetooth > Microsoft Bluetooth Driver
   • For rtump64x64.sys / rtux64w10.sys: Network Adapters > Realtek...
4. Right-click > Properties > Driver tab > Roll Back Driver (if available).
5. If rollback is grayed out, right-click > Uninstall device and check "Delete the driver software for this device."
6. Restart in normal mode and let Windows install the generic driver, or download the latest driver from HP Support (support.hp.com) using your product's serial number.

For Windows Update-related BSODs:

• Go to Settings > Update & Security > View Update History > Uninstall Updates.
• Sort by date and remove the most recent cumulative update.

Step 6: Run HP Hardware Diagnostics

HP builds a dedicated diagnostics tool into most of its devices. Access it by pressing F2 at startup (UEFI Diagnostics) or by downloading HP PC Hardware Diagnostics UEFI from hp.com.

• Memory Test: Run the extensive memory test to detect bad RAM. A failure here means KERNEL_SECURITY_CHECK_FAILURE and random BSODs will persist until RAM is replaced.
• Hard Drive Test: Run the SMART Check and DST (Drive Self Test). A failing SMART status means INACCESSIBLE_BOOT_DEVICE errors will recur.

Alternately, for RAM testing outside of Windows:

• Boot MemTest86 (free, bootable USB) for at least 2 full passes. Any errors = replace RAM.

Step 7: Check BIOS/UEFI Settings

An incorrect SATA mode is a common cause of INACCESSIBLE_BOOT_DEVICE on HP desktops and laptops after a BIOS reset:

1. Press F10 at startup to enter BIOS Setup.
2. Navigate to Storage > Storage Options or System Configuration > SATA Emulation.
3. Ensure the mode is set to AHCI (not IDE or RAID) for SSDs.
4. Also check for a BIOS/firmware update under HP Support > Drivers & Software > BIOS for your specific model (Pavilion, EliteBook, Envy x360, Omen, Victus, etc.).

Step 8: HP Automatic Repair Loop Fix

If the HP laptop is stuck in "Automatic Repair" blue screen loop:

1. Enter WinRE (force restart 3 times or press F11).
2. Go to Troubleshoot > Advanced Options > Command Prompt.
3. Run:

bcdedit /set {default} recoveryenabled No
attrib -r -s -h C:\boot\BCD
bootrec /rebuildbcd

4. If that fails, try System Restore: Troubleshoot > Advanced Options > System Restore.
5. Last resort: Troubleshoot > Reset this PC (choose Keep my files first, then Remove everything only if needed).

HP Printer Blue Screen Note

If you see a blue screen on an HP Envy 4520, Envy Photo 7155, Envy Photo 7855, OfficeJet 4650, OfficeJet Pro 7740, OfficeJet Pro 9015, or other HP printer's LCD panel, this is NOT a Windows BSOD. It indicates the printer's firmware has crashed or the LCD is malfunctioning. Fix: Hold the power button for 15 seconds, unplug power, wait 60 seconds, replug and power on. If the blue screen persists, perform a factory reset from the printer's menu (if accessible) or use the HP Print and Scan Doctor utility on Windows to push a firmware update.

When to Use HP System Recovery

If all software-level fixes fail and HP Hardware Diagnostics shows no hardware faults, use HP Recovery (F11 at boot) to:

• System Restore: Revert to a previous restore point without losing files.
• Factory Reset (Minimized Image Recovery): Reinstall Windows while keeping the HP factory image.
• Factory Reset (Full Recovery): Completely wipe and restore to factory state (data loss — back up first).