Why my computer is no bootable device?

There are a few common reasons why you may see the “no bootable device” error when trying to start up your computer:

Table of Contents

BIOS not detecting boot drive

One of the most common causes of the “no bootable device” error is that your computer’s BIOS is not detecting your boot drive properly. This can happen for a few reasons:

Boot drive is unplugged or loose – Make sure your boot drive (usually the hard drive or SSD) is properly plugged into the motherboard. Reseat the cables connecting it.

Boot order is incorrect – Enter your BIOS settings (by pressing a key like F2 or Delete during bootup) and make sure your boot drive is prioritized first in the boot order.
Dead boot drive – If your boot drive has failed completely, the BIOS will not detect it and you’ll get the “no bootable device” message.

If the BIOS is not detecting your boot drive correctly, it will not be able to load the operating system, resulting in the “no bootable device” error.

Corrupted bootloader

The bootloader is a small piece of code stored on the boot drive that launches the operating system startup process. If this bootloader becomes corrupted or damaged, your computer may not be able to start properly.

Potential causes of a corrupted bootloader include:

Faulty operating system update – A bad OS update can sometimes corrupt the bootloader.

Virus or malware infection – Malicious programs can overwrite and damage the bootloader.
Improper shutdown during OS installation – Turning off the computer incorrectly while installing a new OS can corrupt the bootloader.

To fix a corrupted bootloader, you may need to reinstall or repair your operating system using recovery tools or installation media.

Damaged system files

Critical system files required for the operating system to load properly may become corrupted or go missing. This prevents your computer from completing the startup process.

Causes of damaged system files include:

Hard drive errors – Bad sectors or file system errors on your boot drive can damage system files.

Failed updates – Faulty OS or driver updates may replace system files with corrupted ones.
Malware infection – Malware may modify or delete important system files.

Using System File Checker or your OS recovery options can help replace missing or corrupted system files to potentially resolve a “no bootable device” issue.

Hardware failures

Failing or malfunctioning hardware components can prevent your computer from booting properly:

Failed hard drive – As mentioned previously, if your boot drive is dead or damaged, it won’t be detectable to the BIOS.
Faulty RAM – Bad memory (RAM) modules can cause boot issues and “no bootable device” errors.

Motherboard issues – Problems with the CPU, chipset, BIOS, or connections on the motherboard can result in failure to boot.

Running hardware diagnostics and testing components individually can help identify any failed hardware causing boot problems.

Loose connections

If hardware connections inside your computer are loose or disconnected, it can prevent successful booting. For example:

The boot drive’s SATA or power cable may be loose.
RAM modules may not be properly seated in their slots.
The motherboard power connector may be partially disconnected.

Opening up your computer case and checking that all hardware connections are secure can potentially fixconnection issues leading to boot problems.

How to fix “No bootable device” error

Based on the most common causes above, here are some steps to try fixing when your PC displays the “no bootable device” message on boot:

Check connections – Make sure all cables (SATA, power, etc) are properly connected to boot drive and motherboard.

Inspect boot order – Via BIOS, ensure boot drive is first in the boot order list.
Try removing extra devices – Unplug any unnecessary USB, drives, or disks that may be interfering with boot process.
Reset BIOS – Reset BIOS to default settings in case a setting is preventing boot.

Reseat components – Remove and reinsert RAM modules, cables, and other hardware to reseat connections.
Replace faulty hardware – Swap in known good RAM, boot drive, power supply if you suspect a failure.
Repair bootloader – Use System File Checker or automatic repair to fix bootloader.

Clean install OS – Backup files and perform a fresh OS installation as last resort.

Additionally, here are some tips for troubleshooting “no bootable device” errors:

Try booting from a USB or disc to isolate OS issues.

Access BIOS and check for error codes or alerts about boot issues.
Examine boot drive on another computer if possible.
Remove any recently added hardware/drives.

Check for loose connections, dust, or damage inside the PC case.

Conclusion

The “no bootable device” error during system startup is usually due to the BIOS not detecting the boot drive, a corrupted bootloader, damaged system files, failing hardware, or loose connections.

By examining the boot order, resetting the BIOS, reseating hardware connections, isolating faulty components, and repairing the bootloader or OS as needed, you can typically resolve this error and get your computer booting normally again.

In rare cases of extreme boot drive failure or motherboard issues, replacing faulty hardware may be required to get a computer powering on and loading the OS. But in most situations, the “no bootable device” problem can be fixed with less drastic troubleshooting techniques.

Cause	Solution
BIOS not detecting boot drive	Check connections, boot order, try new SATA cable
Corrupted bootloader	Repair with System File Checker or OS reinstall
Damaged system files	Start in Safe Mode, use System File Checker
Hardware failure	Run hardware diagnostics, replace faulty component
Loose connections	Reseat RAM, SATA cables, power cables

With the right troubleshooting approach, the frustrating “no bootable device” error can often be resolved and return your computer back to fully working order.

Frequently Asked Questions

Why am I suddenly getting a “no bootable device” error?

There are a few reasons you may suddenly start getting this error when your computer was working fine previously:

The boot order was accidentally changed in the BIOS
Connection issues developed with the boot drive or other hardware
Your boot drive has failed or is corrupted

A recent OS, driver, or firmware update caused boot problems
You installed a new drive which changed boot priority

Can a “no bootable device” error be caused by a virus?

Yes, a virus or malware infection can sometimes lead to a “no bootable device” error. Viruses can corrupt or overwrite critical boot files, damage the master boot record, or even erase files required for booting. If malware is suspected, scanning the drive from another computer may help determine if infection is the cause.

What should I do if reseating cables and hardware did not fix the no bootable device issue?

If you still get the error after reseating connections, try resetting the BIOS to default settings, booting from a recovery drive, running hardware diagnostics, checking the boot order, and examining the boot drive for errors. Repairing the bootloader, starting in Safe Mode, or performing a system restore from recovery options may also help resolve persistent issues.

Can a failing hard drive cause the no bootable device error?

Yes, a failing or failed hard drive is one of the most common hardware issues that can lead to this error occurring. If the BIOS cannot detect the boot drive due to drive failure, you will see the “no bootable device” message. Replacing the faulty drive would be required in such a situation.

How can I access my computer’s BIOS to check the boot order?

The key to enter the BIOS settings menu is different depending on the manufacturer, but common keys are F2, F10, Delete, or Esc. Rapidly tapping the key immediately on startup should bring you to the BIOS. Here you can check that your boot drive is properly detected and listed first in boot priority.

If I get the no bootable device error after installing a new OS or drive, what should I do?

Make sure the BIOS is set to boot from the new drive on which the OS was installed. Also confirm the new drive is properly connected via SATA and power cables. If it still won’t boot, you may need to repair the bootloader by reinserting OS installation media.

What is the best way to backup my data if I need to reinstall my operating system to fix the no bootable device issue?

If possible, connect your hard drive to another working computer as a secondary drive and copy your important files to external media or cloud storage. Alternatively, boot your problematic computer from a live CD/DVD and backup data that way prior to reinstalling the OS.

Troubleshooting Examples

Here are some example troubleshooting scenarios for specific “no bootable device” issues:

Just installed an SSD, now getting “no bootable device”

Make sure the SATA cable and power cable are properly connected to the SSD.
Check that the SSD is enabled as first boot option in BIOS settings.
If installing a fresh OS, make sure you have set the SSD as the install destination.

The SATA controller mode may need to be changed to AHCI in BIOS for SSD compatibility.

Was working fine yesterday, now suddenly won’t boot

Reset BIOS to default settings to undo any changes that may be preventing boot.
Boot into Safe Mode or Last Known Good Configuration to diagnose issues.

Run System File Checker to scan for corruption or missing files.
Roll back recent driver updates that may have caused compatibility issues.
Check Event Viewer for critical error messages that could indicate failure.

Error started after BIOS update

The new BIOS version may have a bug or be incompatible. Downgrade the BIOS to a prior stable release.
Reset BIOS settings to their factory defaults.
Older drives may not be supported by the newer BIOS, requiring a firmware update.

Make sure boot order and boot mode (legacy vs. UEFI) are set correctly post-update.

Hard drive clicks repeatedly, no boot

Clicking noises can indicate imminent hard drive failure.
Stop attempts to boot to prevent further damage.

Disconnect and replace the faulty hard drive.
Initialize and format the new replacement drive.
Reinstall operating system and restore data from backup.

Boots to black screen after BIOS splash

Boot into Safe Mode to narrow down issues with loading graphics drivers or startup programs.
Try booting with just one RAM stick, alternating slots to test bad memory.
Reset display drivers by booting into VGA or low resolution mode.

Corrupted Windows files can prevent loading, run Startup Repair from recovery options.

Advanced Troubleshooting Tips

For tricky no bootable device errors, here are some advanced troubleshooting techniques to try:

Boot to a Linux live USB – This will eliminate OS-level issues and determine if hardware failure is the cause.

Remove CMOS battery – Resetting BIOS via battery removal may override quirky settings preventing boot.
Examine event logs – Administrative events in Windows logs can indicate the trigger for failure to boot.
Disable non-essential devices – Remove extra drives, peripherals, and expansions cards temporarily to simplify boot process.

Check connector pins – Use magnifying glass to inspect motherboard socket pins for damage or bent pins.
Try replacement parts – Swap hardware like RAM and hard drives with known good spares to test culprit.
BIOS reflash/update – A bad BIOS flash may require downloading firmware on separate PC and reflashing chip.

Combining these advanced techniques with standard troubleshooting methods can aid in tracking down difficult to diagnose boot issues when simple steps are unsuccessful.

Summary

The “no bootable device” message at startup typically indicates issues with your boot order configuration, bootloader, drive connections, or hardware failures preventing detection of the OS boot partition.

Carefully inspecting boot settings, system connections, hardware health, and OS integrity can reveal the underlying problem. With software repairs, hardware replacement, properly configured BIOS settings, and connection troubleshooting, you can eliminate frustrating boot errors.

Backing up your data and utilizing various system recovery and repair tools is key before making substantial software or hardware changes. With persistence and methodical troubleshooting, you can get your PC booting reliably once again after a “no bootable device” failure.