Failed Boot Sequence Error Fix (Lenovo / HP / Dell) – Causes & Step-by-Step Recovery

If your PC gets stuck at the logo screen or shows “Failed Boot Sequence”, “Boot sequence failed”, or “No bootable device”, it usually means the system cannot find the correct boot device (SSD/HDD) or the boot settings (BIOS/UEFI) no longer match your Windows installation. This guide explains the most common causes and the best proven fixes, including brand-specific tips for Lenovo, HP, and Dell.

Target keywords: Failed Boot Sequence, boot sequence failed, no bootable device, Windows boot error, BIOS boot order, UEFI vs Legacy

What Does “Failed Boot Sequence” Mean?

A Failed Boot Sequence error appears when the firmware (BIOS/UEFI) cannot boot into Windows. In plain terms, your PC is looking for Windows on the wrong device (USB/external drive/network), can’t detect your SSD/HDD, or the Windows bootloader is damaged.

This problem can occur after BIOS updates, power outages, forced shutdowns, SSD/HDD replacement, or when a bootable USB device is connected.

Top Causes of Failed Boot Sequence

1) Wrong Boot Priority (Boot Order)

The most common cause is that the system tries to boot from USB, external HDD, or network/PXE before your internal SSD that contains Windows.

2) SSD/HDD Not Detected

If your SSD/HDD is not recognized by BIOS/UEFI, Windows cannot load. This may be caused by loose connections, a failing drive, or an improperly seated M.2/NVMe SSD.

3) UEFI vs Legacy Mode Mismatch

Windows is installed in a specific boot mode. If your PC is switched to a different mode later (e.g., Windows installed in UEFI/GPT but BIOS is set to Legacy/CSM), boot can fail.

4) Corrupted Windows Bootloader (BCD/MBR)

Repeated forced shutdowns, disk errors, or interrupted updates can damage the boot configuration data and prevent Windows from starting.

5) Secure Boot / BIOS Reset After Update

After a BIOS update or reset, settings like Secure Boot, CSM, or Boot Mode may revert to default. That change alone can trigger the Failed Boot Sequence error.

Step-by-Step Fix (Do These in Order)

Step 1: Unplug External Devices (Quick Win)

Remove all USB drives, external HDD/SSD, memory cards, and docking devices. Then reboot. Many systems attempt to boot from removable devices first.

Step 2: Enter BIOS/UEFI and Fix Boot Order

Power on and repeatedly press your BIOS key (brand-specific keys listed below).
Go to Boot or Boot Priority.
Set Windows Boot Manager (or your internal SSD) as Boot Option #1.
Save changes and restart.

Lenovo Boot Keys

BIOS setup: F1 or F2 (varies by model)
Boot menu: F12
Tip: On some ThinkCentre/ThinkPad models, you can also use the Novo button to access startup options.

HP Boot Keys

Startup menu: ESC
BIOS setup: F10
Boot menu: F9
Tip: HP often labels the internal boot entry as OS Boot Manager.

Dell Boot Keys

BIOS setup: F2
Boot menu (one-time): F12
Tip: Ensure Windows Boot Manager is above Network/PXE in the boot list.

Step 3: Check If the SSD/HDD Is Detected

In BIOS/UEFI, look for Storage, SATA/NVMe, or System Information. If your drive is missing, the issue is likely hardware-related (loose cable, dead drive, or M.2 not seated properly).

Best practice: If possible, power off completely, reseat the drive (desktop users), or run built-in diagnostics (many OEM systems include them).

Step 4: Match Boot Mode (UEFI vs Legacy/CSM)

Try switching the boot mode only if you suspect a mismatch:

Windows 10/11 (most modern PCs): UEFI + GPT is typical.
Older installs: Legacy/CSM + MBR may be used.

If your BIOS has settings like Boot Mode, UEFI/Legacy, or CSM Support, change just one setting at a time, save, and test boot.

Step 5: Run Windows Startup Repair

If the drive is detected and boot order is correct but the error persists, use a Windows installation USB to repair the bootloader.

Boot from Windows USB (use one-time boot menu key like F12/F9).
Select Repair your computer → Troubleshoot → Advanced options.
Choose Startup Repair first (recommended).

Step 6: Repair Boot Records (Command Prompt)

If Startup Repair doesn’t work, try these commands (still inside Advanced options → Command Prompt):

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

After running the commands, restart and check if Windows loads normally.

Step 7: Toggle Secure Boot (If Needed)

Secure Boot can sometimes block booting after firmware changes or certain drive migrations. In BIOS/UEFI, try disabling Secure Boot temporarily, then test boot. If disabling fixes the issue, you can later revisit settings and update drivers/firmware properly.

Step 8: Run OEM Diagnostics (Lenovo / HP / Dell)

If you suspect hardware failure, use the built-in diagnostics:

Lenovo: Use boot menu (F12) or Novo button → diagnostics (options vary by model).
HP: ESC → System Diagnostics (often includes Storage Test and Memory Test).
Dell: F12 → Diagnostics (Dell ePSA tests can detect drive issues).

FAQ (Common Questions)

Do I need to reinstall Windows (format) to fix Failed Boot Sequence?

Usually no. Most cases are solved by fixing boot order, matching UEFI/Legacy mode, or repairing the Windows bootloader.

Can a bad SSD cause Failed Boot Sequence?

Yes. If the SSD is not detected in BIOS/UEFI or fails diagnostics, it may be failing and need replacement.

Why does this happen after BIOS update?

BIOS updates can reset boot settings (Secure Boot, CSM, boot priority). Re-check Windows Boot Manager as the first boot option.

It only happens when a USB drive is plugged in. Is that normal?

This typically means your boot priority is set to USB first. Remove the USB or place your internal SSD/Windows Boot Manager first.

Summary: The Fastest Path to Fix

If you want the quickest checklist, follow this order:

Unplug all USB/external devices → reboot
Set Windows Boot Manager / internal SSD as Boot Option #1
Confirm SSD/HDD is detected in BIOS
Match UEFI vs Legacy/CSM to your Windows installation
Use Windows USB → Startup Repair → then bootrec commands if needed
Run OEM diagnostics (Lenovo/HP/Dell) if hardware is suspected

In most cases, this resolves the Failed Boot Sequence error without formatting or data loss.

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