Why does my computer say no bootable device when I start it?

Seeing the “no bootable device” error when you start your computer can be frustrating. This error indicates that your computer is unable to find a bootable hard drive from which to load the operating system. There are several potential causes for this error, but the good news is that it can usually be resolved with some basic troubleshooting steps.

What does “no bootable device” mean?

When you first turn on your computer, it goes through a boot up process that loads the operating system and gets the machine ready for use. Part of this process involves loading key files and data from a bootable storage device, typically the primary hard drive.

The “no bootable device” error occurs when your computer cannot find a storage device with a bootable operating system installed. Without a bootable device, the computer has nothing to load and cannot proceed past the initial boot stage. This will result in an error message along the lines of:

“No bootable device found. Please restart system.”

The most common reasons why your computer may fail to detect a bootable device include:

  • Hard drive is completely blank or uninitialized
  • Corrupted hard drive or file system errors
  • Disconnected or damaged cables
  • Failed, old, or improperly installed hard drive
  • BIOS not recognizing hard drive
  • Boot order not set correctly in BIOS

If any of these underlying problems are present, it will cause the “no bootable device” error during system startup. Identifying and resolving the specific issue will allow your computer to locate the bootable device again and load the operating system as normal.

How to Fix the “No Bootable Device” Error

There are a number of troubleshooting steps you can take to get your computer booting properly again when faced with this error:

Restart Your Computer

The first step is often the simplest – restart your computer. Shut down fully, wait a few seconds, and power back on. This may allow the BIOS or UEFI firmware to detect the bootable drive properly on the next startup.

Check Connections and Cables

Make sure all the physical connections related to your hard drive are securely attached. This includes power cables, SATA data cables, and any other relevant connectors. Reseat cables fully to ensure a proper connection.

Boot Into BIOS and Check Boot Order

Access your computer’s BIOS settings, usually by pressing a key like F2, F10, or Delete during startup. Once in the BIOS, verify that your hard drive with the OS installed is listed as the first boot device. If not, change the boot order and restart.

Replace Damaged Cables

Faulty SATA cables are a common culprit for boot issues. Swap out any suspect cables for new ones. Try disconnecting other devices and booting with just the primary hard drive connected.

Connect Hard Drive to Another Computer

If possible, connect the hard drive to a different computer as an external drive. See if it is recognized properly and accessible. This can help determine if the drive itself is still good or has failed.

Check Hard Drive Health

Use your hard drive manufacturer’s disk utilities to diagnose the health of the drive. Look for S.M.A.R.T. errors or other indicators of hardware failure. If the drive is damaged, it may need to be replaced.

Try Booting From a Recovery Drive

Create a recovery drive or bootable USB and try to start up from the external device. If successful, you can use it to access your main hard drive and troubleshoot further.

Reinstall or Repair Bootloader

Use recovery tools from your operating system installation media to rebuild the bootloader information. This may fix issues caused by bootloader corruption.

Reset BIOS to Default Settings

Reset BIOS settings to their factory defaults. Old or incorrect settings may be preventing BIOS from detecting the hard drive correctly.

Reinstall or Update BIOS/Firmware

Check for new BIOS or firmware updates from your motherboard or PC manufacturer. Installing the latest update can resolve compatibility bugs.

Initialize or Format Hard Drive

Use Disk Management tools to initialize a new hard drive or perform a full format on an existing drive. This will overwrite old partition and file system data.

Replace Hard Drive

If all else fails, the hard drive itself may be damaged beyond repair. Replace the boot drive with a new, compatible hard drive and reinstall your operating system.

Common Causes of “No Bootable Device” Error

Understanding the root cause of the “no bootable device” error message can help guide troubleshooting:

Disconnected or Loose Cables

If SATA data or power cables are disconnected or become loose from the hard drive or motherboard, the BIOS will not detect the drive at boot. Reconnect cables properly and try again.

Hard Drive Not Detected in BIOS

If the BIOS does not list your bootable hard drive under the boot priorities list, the system will not recognize the drive. Update BIOS, reset CMOS, or replace cables.

Damaged Hard Drive

File system corruption, bad sectors, mechanical failure or other hard drive damage can make partitions unbootable. Check health with disk tools and replace drive if needed.

Incorrect Boot Order in BIOS

When another device such as a USB or optical drive is set as the first boot device, the system will attempt to boot from it instead of the hard drive. Change BIOS boot order.

Old or Incompatible BIOS/Firmware

On older systems especially, a BIOS update may be required for proper support of newer drives. A firmware mismatch can prevent boot.

Empty Hard Drive

Brand new hard drives must be formatted and have an operating system installed to be bootable. Initialize the disk and install OS to resolve.

Corrupted Bootloader

The master boot record or bootloader itself may be corrupted or missing, preventing boot even if drive is otherwise OK. Rebuild MBR or reinstall bootloader.

Faulty Hard Drive Controller

In rare cases, the hard drive controller hardware in your computer could fail, or become disabled in BIOS. Try a different SATA port, enable controller in BIOS, or replace controller.

How to Prevent “No Bootable Device” Errors

You can take steps to reduce the chances of a “no bootable device” error occurring in the future:

  • Keep BIOS updated to latest stable version
  • Use high quality SATA cables for hard drive connections
  • Do not unplug hard drive from system when powered on
  • Safely eject external USB drives before powering off system
  • Install surge protectors to avoid electrical damage during storms
  • Avoid exposing hard drives to excess vibration, magnets, liquids
  • Regularly check hard drive health using S.M.A.R.T. tools
  • Ensure proper airflow and cooling for hard drive
  • Clone or image boot drive regularly for backup
  • Backup critical data to external drives or cloud storage

Taking preventative measures reduces the chances of boot device errors. But if you do see “no bootable device”, stay calm and methodically try each troubleshooting step until your computer boots properly again.

Frequently Asked Questions

Why does my PC say no boot device found?

This error occurs when your PC tries to boot from the hard drive but cannot detect an active partition with a valid operating system installed. Causes include disconnected cables, corrupt bootloader, drive not detected in BIOS, power failure, or failed hard drive.

How do I fix no bootable device Please restart system?

First, restart your PC and enter BIOS to see if the hard drive is listed. If it is, ensure it is set as first boot device. If not detected, reconnect SATA cables, try a different cable or port, reset BIOS to default. A damaged or uninitialized drive may need to be replaced and OS reinstalled.

Why is my hard drive not showing up in BIOS?

If your hard drive is not being detected in BIOS, potential fixes include updating BIOS, reseating SATA cable connections, enabling SATA controllers in BIOS, resolve drive conflicts, clear CMOS, ensure proper power supply voltages, or replace failed cable/drive if needed.

Can a computer work without a hard drive?

No, a functional hard drive is required for a computer to operate properly. Without a hard drive installed, the computer has no operating system, programs, or data storage available to complete the boot process and load an OS. Some limited functionality is possible via external devices.

How do I fix a detected boot failure?

For boot failure errors, first ensure BIOS recognizes the hard drive. Check cable connections, boot order, drive health. Try booting into safe mode, run chkdsk /f, use bootrec to rebuild boot files. If drive is damaged beyond repair, you may need to replace it and reinstall OS.

Why is my second hard drive not showing up?

Secondary hard drives may not show if drive letters conflict with another device, cables are loose, partitions are missing or unallocated, or if the drive has mechanical failure. Check connections, allocate a drive letter, format the drive, or replace failed drives as needed.

Conclusion

The “no bootable device” error can certainly be frustrating, but using the appropriate troubleshooting tips should get your computer back up and running. Check cabling, power, initialize new drives, reset BIOS, repair boot files, and replace faulty hardware as needed. If you methodically test each possibility, you should be able to determine the specific cause and get your system booting in no time.