No Boot Device Available? Fix It in 8 Steps

If your computer shows “No boot device available” or “No bootable device found,” it means the system cannot find a drive with a valid operating system to start from. This guide explains the common causes and walks you through the fixes, from checking BIOS settings to repairing the boot loader.

What This Error Actually Means

When you power on a PC, the BIOS or UEFI firmware runs a self-test, then looks for a boot device—typically a hard drive, SSD, USB stick, or network location—that contains a valid boot sector and operating system files. The “No boot device available” message appears when that search fails. The drive may be disconnected, dead, corrupted, or simply not selected in the boot order.

This error is different from a blue screen or a “Missing operating system” message, which usually means the drive is detected but the OS files are damaged. Here, the firmware itself cannot find any candidate to boot from.

Common Causes and Quick Checks

Before opening your computer, run through these quick checks—they solve a surprising number of cases:

• Remove all USB drives and discs. A leftover USB stick with no OS can cause the system to try it first and fail.
• Restart the computer. A temporary firmware glitch can cause this error once; a clean restart often clears it.
• Check the boot order in BIOS/UEFI. Enter the setup (usually by pressing Del, F2, F12, or Esc during startup) and make sure the correct drive is listed first.
• Look for a “Boot Menu” key. Many systems let you press F12 or F11 at startup to manually pick a boot device—useful if the default order is wrong.

If none of these work, move on to the hardware and software fixes below.

Fix 1: Check Drive Connections and Power

For desktop PCs, a loose SATA or power cable is a common cause. Shut down, unplug the power cord, open the case, and reseat both ends of the data cable and the power cable on the drive. For laptops, the drive is often in a small compartment—reseating it may help, but if you are not comfortable, seek professional help.

If you recently added a new drive, ensure it is properly connected and that the system recognizes it in BIOS. Enter setup and look for the drive in the storage or SATA configuration list. If it does not appear, the drive may be faulty or the cable may be bad.

Fix 2: Change the Boot Mode (UEFI vs. Legacy)

Modern PCs use UEFI, but older drives may be formatted for legacy BIOS (MBR). If the firmware is set to UEFI mode and the drive is MBR, or vice versa, the system will not see it as bootable. In BIOS setup, look for a setting called Boot Mode, UEFI/Legacy, or CSM (Compatibility Support Module).

• If your drive was installed with Windows 7 or older, it may need Legacy mode.
• If your drive uses GPT (common for Windows 10/11), it needs UEFI mode.

Switch the mode, save, and restart. If the error persists, try the other mode. This fix is especially common after cloning a drive or moving it to a new computer.

Fix 3: Repair the Boot Loader (Windows)

If the drive is detected in BIOS but still won’t boot, the boot configuration data (BCD) may be corrupted. You can repair it using Windows Installation Media:

1. Create a Windows installation USB on another computer (Microsoft’s Media Creation Tool works).
2. Boot from the USB, choose your language, and click “Repair your computer” instead of “Install now.”
3. Select Troubleshoot → Advanced options → Command Prompt.
4. Type bootrec /fixmbr and press Enter.
5. Type bootrec /fixboot and press Enter.
6. Type bootrec /rebuildbcd and press Enter.
7. Restart the computer.

This repairs the master boot record and rebuilds the boot configuration. If you get an “Access denied” error on /fixboot, try bootsect /nt60 sys instead.

Fix 4: Check for a Dead or Failing Drive

If the drive is not detected in BIOS even after reseating cables, it may be dead or failing. Listen for unusual clicking or beeping sounds. On a desktop, try connecting the drive to a different SATA port or using a different cable. On a laptop, you can often remove the drive and connect it to another computer via a USB adapter to see if it shows up.

If the drive is detected but makes noise or is very slow, back up your data immediately if possible. A failing drive can die completely at any moment.

Fix 5: Reset BIOS/UEFI to Defaults

Sometimes a misconfigured BIOS setting (like an incorrect SATA mode) can cause this error. Enter BIOS setup and look for an option to Load Defaults or Reset to Factory Settings. Save and exit. This restores the default boot order and SATA settings, which often resolves the issue.

Note: If your system uses RAID (common on older desktops), the SATA mode must be set to RAID or AHCI depending on how the drive was originally configured. Changing it can cause the same error, so if you reset defaults and the error appears, try switching between AHCI and RAID modes.

Frequently Asked Questions

Why did I get “No boot device available” after a power outage?

A sudden power loss can corrupt the boot configuration or cause the firmware to lose its settings. Try resetting BIOS defaults first, then repair the boot loader using Windows installation media if needed.

Can I fix this without losing my files?

Yes, in most cases. The fixes above (reseating cables, changing boot mode, repairing the boot loader) do not erase data. Only if the drive is failing or you need to reinstall Windows would you risk data loss. Always back up if you can.

Is this error the same as “No bootable device found”?

Yes, they are essentially the same message with different wording. Both mean the firmware cannot find a valid boot device. The fixes are identical.

How do I know if my hard drive is dead?

If the drive does not appear in BIOS even after reseating cables and trying different ports, it is likely dead or unplugged. If it appears but makes clicking noises or is extremely slow, it is failing. You can test it by connecting it to another computer as a secondary drive.

Will reinstalling Windows fix this?

Reinstalling Windows will fix the boot loader, but it will erase your files. Try the repair steps first. If the drive is not detected at all, reinstalling will not help—the problem is hardware.

Can a USB drive cause this error?

Yes. If a USB drive is plugged in and the boot order lists USB first, the system may try to boot from it and fail. Remove all USB devices and restart.

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