What To Do When PC Says “Reboot and Select Proper Boot Device”

If you’ve encountered the “Reboot and select proper boot device” message, your computer is unable to locate the hard drive that contains your Windows operating system installation. In other words, your computer doesn’t know where Windows is installed, so it can’t continue starting up.

This error can affect any type of hard drive that is used as an operating system’s installation drive. In some cases, the cause is fairly minor; for instance, an incorrect boot order in the BIOS, or a USB device being prioritized first. In others, it may point to a more serious issue, such as corrupted boot files, an inactive system partition, or a failing drive.

No matter what’s caused your system’s boot issues, rest assured — your data is unlikely to be permanently lost. In this guide, we’ll go over some common causes of the “Reboot and select proper boot device” error message, and how to troubleshoot for each one. 

Remember: even if you’re unable to troubleshoot the error yourself, all is not lost. If all else fails, Secure Data Recovery offers professional data recovery services to retrieve files from unresponsive drives.   

Cause of Reboot and Select Proper Boot Device Error 

Before we talk about fixes, it helps to try and understand why the “Reboot and select proper boot device” error is appearing in the first place. In most cases, Windows isn’t missing; it’s just reachable as a result of a configuration, disk, or hardware issue.

Some causes can be resolved safely through settings and software checks, that we’ll walk you through in the following sections. Others, however — especially hardware-related issues — should be treated with more caution, as continued troubleshooting can worsen data loss.

Configuration / Firmware Issues

Configuration and firmware issues are among the most common ones to address — and often the safest:

• Incorrect boot order causing the system to look at the wrong device first
  
• External bootable devices (USB drives, external hard drives) connected or detected during startup
  
• Legacy Boot enabled on systems that require UEFI
  
• BIOS/UEFI updates or resets that reverted boot settings

Disk and Partition Issues

These issues affect the way in which your Windows boot files are located:

• Inactive system partition that prevents Windows from loading
  
• Corrupted boot records, such as MBR, BCD, or EFI data
  
• Missing or damaged system files due to improper shutdowns or disk errors

Hardware Issues (High Risk)

If your problem is hardware related, and caused by one of the following, then that’s a signal of a more serious problem that will need professional assistance to resolve:

• Loose or failing drive connections
  
• Physically failing HDD or SSD, often accompanied by clicking, freezing, or detection issues

What to Avoid Before You Start

Finally, before you move on to attempting any fixes, it’s important to understand the types of actions that can make the situation worse — and in some cases, even permanently erase your data. When a system won’t boot, it’s tempting to try what seems like the fastest, easiest solution; but some “quick fixes” come with serious risks. 

Here are a few quick fixes that you should either completely avoid, or at least, approach with extreme caution:

• Factory resets reinstall Windows by overwriting the system drive, which can permanently delete personal files.
  
• System Restore may roll Windows back to an earlier state, but restore points often exclude recent files, leading to unintended data loss.
  
• Startup Repair, while useful in some cases, can rewrite boot records or system files. If the drive is already unstable, this may reduce recovery options.

In short, avoid guessing. If the data on your system is important to you, pause before using aggressive repair tools. Your first attempt is often the safest one.

How To Fix “Reboot and Select Proper Boot Device”

In this section, we’ll walk you through some step-by-step troubleshooting methods and fixes, ordered from lowest risk to highest risk. Start with Fix 1 and work your way down the list until your computer is able to boot normally. 

However, if you encounter signs of hardware failure, or your system drive isn’t detected in the BIOS, then stop immediately. You can request help 24/7 to learn more about SSD and hard drive recovery options.  

Method 1: Check BIOS / UEFI Boot Order (Low Risk)

The “Reboot and select proper boot device” error often occurs when your system is trying to boot from the wrong device. This tends to happen after connecting a USB drive, installing new hardware, or changing firmware settings. If this is what’s causing your error, the fix is straightforward. 

To check and rectify your computer’s boot order:

1. Restart the computer.
   
2. Press the BIOS/UEFI access key during startup (commonly F2, F10, DEL, or ESC).
   
3. Navigate to the Boot or Boot Priority section.

4. Set the drive containing Windows (usually the internal HDD or SSD) as the first boot device.
   
5. Save changes and restart.

If your Windows is able to load normally afterward, the issue was just a misconfigured boot order, and you’re all set.

Method 2: Reset BIOS to Default Settings (Caution)

If the boot order looks correct, but you’re still receiving the same error message, you can try resetting your BIOS to factory settings and rebooting your computer.

This helps if:

• A BIOS update altered settings
  
• Firmware values were changed accidentally
  
• The system previously booted correctly

Warning: Resetting BIOS to default settings will remove all your custom settings, including overclocking, RAID configurations, or manual drive settings. If you have a custom-built PC, we strongly recommend against this, unless you’re sure of your configurations.

How to reset safely:

1. Restart the computer.
   
2. Press the BIOS/UEFI access key during startup (commonly F2, F10, DEL, or ESC).

3. Look for Load Setup Defaults, Load Optimized Defaults, or similar
   
4. Save and reboot

If your system is still unable to boot, continue to the next method.

Method 3: Disable Legacy Boot and Enable UEFI (Caution)

On newer systems, enabling Legacy Boot (CSM) can prevent Windows from loading if it wasn’t installed in UEFI mode. 

When this applies:

• Windows was installed on a UEFI-based system
  
• Legacy/CSM mode was enabled recently
  
• The system previously booted without issues

If you’re unsure how your Windows was installed, or your computer uses older hardware or MBR-only configurations, do not attempt this fix.

If you’re sure you want to attempt this fix, then switch modes by following these steps:

1. Enter BIOS/UEFI
   
2. Go to Boot Options
   
3. Disable Legacy Boot / CSM
   
4. Enable UEFI Boot
   
5. Save and restart

If your computer is still displaying the same “Reboot and select proper device” error, then move on to the next method.

Method 4: Check Startup Disk or Active System Partition (High Risk)

In some cases, the system partition that Windows relies on is marked as inactive — this prevents startup from carrying on as usual.

What to know:

• The system partition contains boot-critical files
  
• Marking the wrong partition as active can make recovery harder
  
• These fixes are not beginner-safe

If you suspect an inactive system partition, stop here and consult a professional. DIY attempts to correct partition status often involve command-line tools which can overwrite boot records or erase partitions. 

Preventing Boot Device Errors in the Future

You can never fully eliminate the risk of ever encountering a boot error of any kind. However, a few preventative habits can greatly reduce the chance you see the “Reboot and select proper boot device” message again:

First, shut your computer down properly regularly rather than relying on sleep or forced restarts which can corrupt boot files over time. Then, before you next boot up your computer, make sure any external drives, USB flash drives, or bootable media are disconnected during startup — these can confuse the boot order and trigger errors. Plug them back in after your computer has finished booting up. 

Next, maintain your system’s stability by periodically checking for BIOS and firmware updates from your manufacturer’s official site. Don’t overdo this, and update only when necessary. Improper updates or interruptions can cause serious boot issues. Using a surge protector or uninterruptible power supply (UPS) helps protect your system from power fluctuations that can damage drives or corrupt firmware.

Finally, try to always maintain regular backups of your important data. In most cases, your data can likely be recovered, even when a boot device fails — but having a backup means your mind is always at ease, and the issue is merely an inconvenience; never a crisis. 

When To Stop Troubleshooting and Contact Experts

Some boot errors are simply not safe to troubleshoot at home. If any of the conditions below apply, stop further fixes and seek professional help immediately.

Stop troubleshooting immediately if:

• Your system drive does not appear in BIOS/UEFI at all
  
• You hear clicking, beeping, grinding, or buzzing sounds from the drive
  
• The computer freezes, crashes, or reboots repeatedly during startup
  
• The system partition or boot records appear damaged or inactive
  
• The data on your drive is critical or irreplaceable

These symptoms often indicate hardware failure, firmware corruption, or severe boot-sector damage. If you continue attempting DIY fixes at this point — especially command-line repairs, partition changes, or repeated reboots — it can greatly increase your risk of permanent data loss. 

However, a professional recovery service like Secure Data Recovery is able to resolve these situations because:

• Drives are evaluated in cleanroom environments when needed
  
• Engineers create a sector-by-sector image before any repair
  
• Thanks to advanced tools, reconstruction of boot records, firmware, and partitions are possible without risking original data

If you’re dealing with a “Reboot and select proper boot device” error, or any other form of data loss that you’re struggling to resolve at home, we’re here to help. 

Start your case today by calling 800-388-1266 or get a free quote by filling out our online form. We offer diagnostics at no cost, free quotes, and a No Data, No Recovery Fee as part of our standard service.