Reboot and Select Proper Boot Device: How To Solve This Windows Issue

The Reboot and Select Proper Boot Device is an error quite common in Windows. This is the first sign that shows an error in the computer’s BIOS.

Reboot and Select Proper Boot Device

However, we can get rid of this issue in various ways to make the booting system function.

Keep reading to find out more information!

What Does Reboot and Select Proper Boot Device Mean

In the Windows Operating System, this error means that something is wrong in the BIOS. The computer is unable to locate the boot device that contains the operating system. Thus, the user has to restart the system to get into the computer’s BIOS to find and select the correct boot device. This device will contain the operations required for the proper boot.

What Causes Reboot and Select Proper Boot Device Error

“Reboot and proper boot-device” issue occurs because of these possible reasons given below.

– Physical Issues

This issue occurs when the boot disk is not connected to our computer’s hardware. It is either a damaged or failed boot disk, faulty cables or SATA slots or a dead hard drive disk.

– Software Issues

This can include an inactive boot partition or a damaged/corrupted Master Boot Record. Its BIOS can have issues due to a wrong boot sequence, lost boot-files or corrupted operating system.

– The Order of Boot and Boot-files Are Wrong

When the boot files are in the wrong order, the computer recognizes the wrong device for its booting system operations. Unfortunately, this file does not contain the operating system to boot the computer. Thus, we end up seeing the error message on the screen.

– Legacy Mode Is either Active or Inactive

If the system is not BIOS but instead UEFI, it is important to see that the Legacy mode is inactive. Because if it is active, then we can have this rebooting issue and error message.

– An HDD Failure Can Cause This Issue

There can be issues with the computer’s disk drive due to which the BIOS is unable to fetch the operating system and boot the computer properly.

An HDD Failure Can Cause This Issue

Issues can include; damaged, unattached or outdated disk drives.

– The System Partition Is in an Inactive Mode

When the system partition is inactive, BIOS does not work properly and cannot detect the files. Thus, it is unable to detect the operations file required for the booting system. Therefore, we get this error message in return.

– The Windows Registry Needs a Clean-up

When the Windows registry is overloaded by junk or uninstalled files, it can corrupt the computer system and a malfunction can occur in the BIOS. It can make the booting process really slow as well. This is another reason for us to receive the error message.

How To Resolve Reboot and Select Proper Boot-device Errors

Now that we know why this problem arises, we will see how to fix this malfunction by using different solutions.

– Check and Change the Boot Order

This is the most common reason for the “Reboot and select Boot Device” error. This is the first issue we need to resolve or look into. Here’s what we have to do to change the boot order:

  1. Restart our computer.
  2. Press a dedicated key on the keyboard and enter into the BIOS menu. The key we have to press will be seen on the monitor that appears when we turn our computer on. They could be any of these; Esc, Del, F2, F8, F10, or F12.
  3. Now open the Boot tab.
  4. Change the boot order on the PC and list the computer’s hard drives.
  5. Save the changes made and restart the computer.

– Hard-Disk Should Be Working Properly

Check and make sure the HDD has not failed. Obvious signs of failing hard-disks are; slow computer performance, strange or weird noises and several corrupted files accumulated on our PCs. Update the HDD if it is an old version or check if it is attached to the motherboard properly. If it isn’t attached properly, then switch off the computer, attach the hardware again and switch on the computer.

– Disable the Legacy Boot

This step should be taken into consideration if our system is not BIOS but UEFI. Because in the UEFI system, if the legacy mode is on, then it can show us the boot error.

Disable the Legacy Boot

Here’s how we can disable the Legacy mode in a computer:

  1. Restart the computer.
  2. Go to the UEFI menu by pressing the particular key like; F2, F8, F12, or the Del key. The key to press will be shown on the screen after we start up our computer.
  3. Now, go to the Security tab and then Legacy support.
  4. Turn off the Legacy option.
  5. Save the changes we have made.
  6. Close the menu.
  7. Restart the computer and check if the error is gone.

– Run Diskpart

Check if the main partition is set as inactive. In case it is, then the boot error message will be shown to us. Therefore, we have to activate it. To make it active, we have to run the diskpart file. For that, original Windows installation media is required. Read the below instructions.

  1. Insert the Windows CD and boot it from the media.
  2. Open the troubleshoot menu or System Recovery Options and go to the Commands Prompt.
  3. Search “diskpart” and press Enter.
  4. Type “select disk 0” or to see a full list of available disks, type “list disk”.
  5. Press Enter and a tab will open.
  6. Type “list partition” and press Enter again.
  7. Now type “select partition 1”. This is the main partition of our computer.
  8. Type “active” and press Enter again.
  9. This should now set our computer partition back to active and the issue should be resolved.

– Clean the Registry

Unclean Registry can create major problems for our computers. If our computer’s Registry is full of uninstalled applications, we may have to clean and optimize it to improve the computer’s overall performance. Auslogics Registry Cleaner is a free of cost tool used to make changes in the Registry. 

If we do it manually, we have to create a system restore point first, in case something goes wrong. However, we have to first check if our System Restore is activated on our PC or not. Here is what we have to do:

  1. Search System Restore in the search bar.
  2. Got to the option Create a Restore Point.
  3. Click on System Protection.
  4. Now select the drive we wish to check and go to Configure.
  5. Here, we have to make sure that the “Turn on system protection” feature is activated.
  6. Once the protection is activated safely, move on to create a System Restore Point.
  7. Click on the Start button.
  8. Open the Control Panel and go to System Maintenance and then System.
  9. On the left side, we’ll see “System protection”. Click on it.
  10. Now click the “Create” button.
  11. Now we will compose a description for the restore point. It can be the data we are creating or the reason why we are doing it. For example, “before Registry cleanup”.
  12. Click on the Create button again.
  13. Go through the Registry and delete the leftover keys and files like non-existing shared deleted files, spam startup entries, etc.
  14. The issue should be resolved.

– Check the Power Cable Connected to the HDD

The HDD that stores the operating system program must be connected to the motherboard with the help of a power cable. In case the cable is broken, frayed or improperly connected, we can receive the “reboot and select proper boot device” error. This is because the hard drive isn’t detected by the computer.

Check the Power Cable Connected to the HDD

  1. Shut the computer.
  2. Find the power-cable that is attached from the hard disk to the motherboard and see if it is physically damaged or if its connection is properly done.
  3. If it looks like it is connected properly and the error still exists, then remove the cable from the computer and test it on another computer.
  4. If the error occurs on the new testing computer as well, it means the cable is faulty and we have to replace it with a new one.
  5. And if the error doesn’t occur on the new testing computer, we have to re-attach the cable to that faulty computer properly.
  6. Move on to look for other solutions to this error.

– Boot Drive Should Be Detected in the BIOS

Sometimes the Boot drive is not detected by the computer’s BIOS. In order to resolve this issue, follow the below steps;

  1. Reboot the computer.
  2. Press the post-screen specific key to get into our computer’s BIOS.
  3. We will be able to see all the detected devices by the BIOS on the screen. This will include the computer fans, hard-disk drives, and any other hardware devices that are connected to the computer; like a DVD/CD drive.
  4. If the hard-disk is not listed in there, we have to shut down our computer.
  5. Open up the computer and do either of the two options. 
  1. A) Connect the hard-disk drive to another SATA slot. 
  2. B) Use another SATA cable to connect the hard disk drive to any other SATA slot in the motherboard.
  1. Reboot into the BIOS again and if the hard-disk drive is detected now. If it is detecting, then we know the problem was either in the cable or the SATA port on the Motherboard.
  2. And if it still doesn’t work, then the boot disk may be corrupted, failed, damaged or dead.

– Set BIOS to “Defaults”

This solution is not common but sometimes when the computer’s BIOS is not set to its default values, it can cause instability issues. And this instability may be the reason for the “reboot and select proper boot device” error. To access this, we have to get into the BIOS. Please select boot device and look for the option that allows us to “load optimal defaults”. Accept that and restart the computer again. The problem should be fixed.

– Use Command Prompt To Activate an Inactive-Partition

Set the primary drive partition on the boot disk as active to avoid the “reboot and select proper boot device” error message. Use Windows installation media disk or recovery disk as a media boot priority in the BIOS. When we see options like; repair, restore, or recover your computer. Click on any of them and we’ll either see the System Recovery Options tab on Windows 7 or Vista or a Troubleshoot screen on Windows 8. The error, Reboot and select proper boot device on Windows 10 is resolved similarly as done on Windows 8. Below are the instructions:

  1. Choose the command-prompt from the list and type “diskpart” and press enter.
  2. Then type the command line “list disk”. Press Enter again.
  3. Then use the command line “select disk 0”. Or any disk with the inactive-partition and press the Enter button.
  4. Type “list partition 1” or any inactive-partition and press Enter.
  5. Then type active and press Enter to mark it as active Partition.
  6. Diskpart will show that the partition is now active.
  7. Exit the command line and restart the computer.
  8. The error should be resolved.

– Check and Fix the Windows Boot Files

If the error is not in BIOS and there is no physical problem with the hard drive, then try repairing the Windows boot-files and check if they are corrupted and causing the error. Again, a media installation disc or repair disc is needed for this task.

Check and Fix the Windows Boot Files

  1. Insert the repair disc into the CD drive. You may have to make the BIOS boot from this disc.
  2. Once the Windows setup screen is shown, don’t click on “Install Now”, instead click on “Repair Your Computer” to get into the Windows Recovery Environment.
  3. Now run the command prompt.
  4. For the Legacy BIOS users, type in the following command lines and hit enter after each one:
  • Bootrec /fixmbr and press enter.
  • Bootrec /fixboot and press enter.
  • Bootrec/rebuildBCD and press enter.
  1. And for the UEFI users, just type in this command; bcdboot C:\windows [the letter being your hard disk drive].
  2. Once these steps are completed, exit the command prompt and reboot the computer. If the problem remains, then it wasn’t the boot-files that were causing the issue.


1. How To Fix Boot Device Not Found or Reboot and Select Proper Boot Device Error?

  1. Press the Power button to start the computer. Immediately after this, repeatedly press the F9 key to enter into the BIOS setup menu.
  2. Press F9 on the BIOS setup menu to load and restore the BIOS Setup default setting.
  3. Once loaded, press F10 to save the changes and exit.

2. How to Manually Select the Boot Device?

  1. Restart the computer and a message will pop up, “Press F12 Boot for boot Menu” or “Press Del for Setup”.
  2. Once entered into the boot menu, use the up and down arrows to select the device you wish to boot from.


After reading this article, we have the knowledge on how to solve the reboot and select the proper boot device malfunction.

Here are the key takeaways;

  • During a start-up process, if we have faulty cables or BIOS issues, the first sign is a “reboot and select proper boot device” error message shown to us.
  • Boot-files or Boot disk may have a problem in them due to which this error occurred.
  • Faulty SATA slots or cables might have caused this issue.

We hope you learned valuable information from this article. Thank you for reading!

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