By Bryce / Last Updated July 16, 2020

Content
The Case: No boot device available error in Windows 7
Possible reasons for “No boot device available” error
Fix “No boot device available” in Windows 7/8/10 effectively
Conclusion

The Case: No boot device available error in Windows 7

"Help! I have a Dell Inspiron laptop that Windows 7 installed on and it always works well. But I receive “No boot device available” prompt when I start up it. Then, I press F1 to restart my computer but this message still appears. What happened to my computer? How can fix “No boot device available” error in Dell computer and boot it normally? Any advice will be appreciated!"

Possible reasons for “No boot device available” error

Generally speaking, “No boot device available” error happens out of the following reasons:

  • Boot from disk that doesn’t contain operating system.

  • MBR or boot sector on the bootable disk is corrupted.

  • The bootable disk is physically damaged

  • You compute is infected with virus.

And this error may appear with different message like “No boot device – insert boot disk and press any key”, “Boot Device Not Found”. Please install an operating system in your hard disk” or “No Boot Device Found. Press any key to reboot the machine.”

Fix “No boot device available” in Windows 7/8/10 effectively

After realizing the possible causes for boot device not available, it’s time to see how to fix it with useful ways.

Fix 1. Check boot order and reset BIOS settings to default

To ensure that you boot from right bootable hard drive, you can press certain key to enter BIOS interface while restarting to check boot order. If the disk that you boot computer from is not the right one, press “+” or “-” to set the bootable hard drive as the first in boot order. After that, save changes and restart computer to see whether the error disappears. If the error still exists, try to reset BIOS to default settings by steps given below:

1. Turn off your computer and wait for a while.

2. Restart the computer and press certain key to enter BIOS Setup menu.

3. On the BISO Setup interface, press certain key to select and load the BIOS Setup Default settings.

4. Save changes exit and follow the prompt to restart computer.

PS.: If you are unsure about the key to enter BIOS, you can refer to the user manual of your computer.

Fix 2. Perform a hard reset

If you still meet No boot device available error, you can try to perform a hard reset to restore functionality. Here are detailed steps:

1. Turn off your computer. Remove all external peripheral devices from your computer.

2. Remove AC adapter and battery from your computer.

3. Press and hold the power button for about 15 seconds to drain all the residual energy.

4. Put the battery back and plug the AC adapter into your computer.

5. Turn on your computer to see if it boot normally.

Fix 3. Run Startup Repair with Windows installation disc

To fix “No boot device available” error automatically, you can turn to Windows Startup Repair. Look at the following steps:

1. Insert your Windows installation disc to your computer and boot from it.

2. In the Install now screen, click “Repair your computer”.

3. In the System Recovery Options window, select “Startup Repair”.

Fix 4. Run Bootrec commands with Windows installation disc

If Startup Repair cannot solve the error, you can try to run Bootrec commands to fix MBR and boot sector within the following steps:

1. Boot computer from Windows installation disc and choose “Command Prompt” in the System Recovery Options window.

2. In Command Prompt window, input command lines below and press Enter after each.

  • bootrec /fixmbr

  • bootrec /fixboot

  • bootrec /scanos

  • bootrec /rebuildbcd

3. Exit from Command Prompt interface and restart your computer.

Fix 5. Fix damaged MBR without Windows installation disc

If the MBR of your system hard drive is damaged and you have no Windows Installation disc, you can turn to a third party safe and useful tool – AOMEI Partition Assistant Standard. It owns Make Bootable Media and Rebuild MBR functions. Thus, you can use it to create a bootable device with itself embed. Then, you can boot the Windows 7 computer from the created bootable media and rebuild MBR.

To rebuild corrupted MBR, free download AOMEI Partition Assistant Standard and refer to the detailed steps presented in the following context.

1. Connect a USB drive to a working computer. Install and run AOMEI Partition Assistant Standard. Choose “Make Bootable Media” and follow the wizard to continue.

Make Bootable Media

2. After creating a bootable USB drive successfully, insert it to the computer that “No boot device available” error appears and boot from it.

3. You’ll see the main interface of AOMEI Partition Assistant Standard. Right-click the system hard drive and choose “Rebuild MBR”.

Rebuild System Disk Mbr

4. In the pop-up window, choose the type of MBR for the current operating system.

Choose Mbr Type

5. Back to the main interface, click “Apply”>“Proceed” to perform this task.

Apply

Notes:

  • AOMEI Partition Assistant Standard is with high compatibility, which can work with Windows 10/8.1/8/7, XP, and Vista.

  • Apart from fixing MBR, this software enjoys many other functions like wiping hard disk drive. And you can get more advanced features like cloning system disk, if you upgrade it to Professional version.

Conclusion

When you are trapped in boot failure with “No boot device available” error in Windows 7/8/10, find out the most proper one among fixes presented above to fix this error. If you are still unable to boot Windows computer successfully, try to check the bootable hard drive or run anti-virus software.