Windows 10 Won't Boot? Here's How to Fix It

Computer problems are incredibly frustrating, but there’s nothing worse than when you can’t even reach the desktop because Windows 10 won’t boot anymore. Troubleshooting this issue might seem unrealistic for casual PC users who must resort to the tools provided before boot.

Nevertheless, you should be able to fix system startup problems, whether you get the inaccessible boot device error, the Your PC ran into a problem and needs to restart message, or another Blue Screen of Death error.

Windows 10 Won’t Boot?

Check out the following solutions to fix your operating system if it no longer boots.

1. Unplug external storage devices

It’s possible that your BIOS is configured to read external storage devices, according to the BIOS boot order. However, you can quickly fix this problem by unplugging all removable storage drives, like external hard disks, memory cards, and USB sticks. Then, try to boot Windows.

2. Check your HDD or SSD

If your HDD or SSD is not properly plugged in, your computer won’t be able to read the storage device and start your operating system. It’s easy to check this if you have an external storage device with Windows installed, which is attached to the PC through a USB cable.

Just unplug and replug the device. You should also try using a different USB port in case it’s malfunctioning. Furthermore, it’s a good idea to try using another cable in case the current one is damaged in any way.

3. Check your battery

Laptop battery problems can prevent Windows 10 from booting on your computer. If you’re low on battery, make sure to plug it into a power source. And, if that doesn’t do the trick, remove the battery and leave the laptop connected to a power source.

It’s important to keep track of these steps and try one scenario at a time, in order to determine the culprit and find a long-term solution. For example, if your battery is to blame, you will have to replace it with a new one. But it’s also possible that your charger is not compatible with the laptop, its cable doesn’t properly connect in the laptop or the power source, the laptop’s power source needs repairs, or something else.

4. Start Windows 10 in Safe Mode

Try to start Windows 10 in Safe Mode in order to enter a troubleshooting mode that allows you further investigate your computer’s boot problems. It means disabling non-essential components, such as drivers and services that might be causing system boot errors.

How to start Windows 10 in Safe Mode:

Interrupt the startup sequence three times in a row to enter Windows 10 troubleshooting mode
Go to Troubleshoot > Advanced options > Startup Settings
Click Restart
Press F5 to enable Windows Safe Mode with Networking
If Windows still won’t boot, retrace the steps above and press F4 to enable Safe Mode (without networking features)

5. Skip the Windows 10 bootloader

If you’re having trouble trying to start Windows 10 in Safe Mode, you can skip the bootloader tool using Command Prompt.

Start Windows in troubleshooting mode
Visit Troubleshoot > Advanced options
Launch Command Prompt
Pick your PC account and enter your password

Enter the following command:

bcdedit /set {default} bootmenupolicy legacy

Exit Command Prompt and try to boot Windows 10

6. Check disk drivers

If you successfully get past the Windows boot sequence and start the operating system in Safe Mode, you should check your disk drivers with the help of Device Manager. For instance, you can quickly reinstall the disk devices, update obsolete drivers, or roll back incompatible drivers. Here’s what you have to do.

How to reinstall disk devices:

Right-click the Start button and select Device Manager
Expand the Disk drives category
Right-click your storage device from the list and select Uninstall device
Click Uninstall to confirm
Open the Action menu and select Scan for hardware changes. Windows should auto-reinstall the missing device

How to update disk drivers:

In Device Manager, right-click the disk drive and select Update driver
Click Search automatically for drivers
If you get the The best drivers for your device are already installed message, click Search for updated drivers on Windows Update

A better solution is to use a driver update tool that keeps all your drivers updated to the latest version. Plus, you won’t risk getting an incompatible driver. On the other hand, if you already installed an unsupported driver, you should roll it back.

How to roll back disk drivers:

In Device Manager, right-click the disk drive and go to Properties
Switch to the Driver tab
Click Roll Back Driver and follow the instructions. If the button’s greyed out, you can’t complete the rollback since there’s no previous driver on your PC

7. Temporarily disable Driver Signature Enforcement

If you’re attempting to install drivers that haven’t been signed by Microsoft, Windows 10 won’t allow you as long as the Driver Signature Enforcement feature is enabled. You have two options in this case: either opt for Microsoft-signed drivers or disable Driver Signature Enforcement.

How to temporarily disable Driver Signature Enforcement:

Interrupt the Windows startup sequence three times in a row to enter Advanced Startup mode
Select Troubleshoot > Advanced options > Startup Settings
Click Restart
Press F7 to disable Driver Signature Enforcement
Start Windows as usual and install the non-Microsoft-signed drivers
Retrace the steps and press F7 to re-enable Driver Signature Enforcement

If Windows won’t boot, disable Driver Signature Enforcement from Command Prompt:

In Advanced Startup mode, go to Troubleshoot > Advanced options > Command Prompt
Type bcdedit /set testsigning on and press Enter
If you get the The operation completed successfully message, try to boot to Windows. Else, if it says Protected by Secure Boot policy, you have to disable Secure Boot from the UEFI firmware
Install your drivers
Press Win key + R, type cmd, and press Ctrl + Shift + Enter to open Command Prompt as admin
Run bcdedit /set testsigning off to re-enable Driver Signature Enforcement

How to disable Secure Boot from the UEFI firmware:

In Advanced Startup mode, select Troubleshoot > UEFI Firmware Settings
Click Restart
Once you access the BIOS setup mode, go to the Authentication area
Set Secure Boot to Disabled
Save the current BIOS configuration and exit
Disable Driver Signature Enforcement from Command Prompt
Install the drivers
Re-enable Driver Signature Enforcement
Go back to BIOS to re-enable Secure Boot

8. Uninstall recent software and system updates

You might be experiencing boot problems with Windows 10 due to software programs you have recently installed on your computer. For example, if you have two anti-malware applications installed, their real-time engines could clash and cause system stability issues as a result.

However, you should be able to fix this by uninstalling the conflicting apps. Similarly, if you have started having boot problems after a recent system update, you should remove it from your PC.

Start Windows 10 in Safe Mode
Press Win key + R, type appwiz.cpl, and press Enter
Double-click an application and proceed with the removal operation
Click View installed updates on the left side
Click the Installed On column to sort the updates (newest first)
In the Microsoft Windows group, double-click the first update and uninstall it
Try to restart Windows normally now

9. Fix startup problems

You can use the Startup Repair troubleshooting tool to fix OS boot issues. However, you must first create a Windows 10 installation media on a disc or removable storage device using another computer.

How to create Windows 10 installation media:

Plug an empty USB pen drive into your computer
Download Media Creation Tool from the official website
Fire up the tool
Use the instructions to create a Windows installation media disk

How to repair startup issues:

Make sure the Windows installation media disk is connected to your PC
Interrupt the boot sequence three times to enter troubleshooting mode
Go to Troubleshoot > Advanced options > Startup Repair
Log in with your Microsoft account if requested
Follow the instructions to fix startup problems

10. Use the BCD command

You can try to fix Windows 10 boot problems by entering a couple of lines of code in Command Prompt using BCD (Boot Configuration Data).

Access Advanced Startup mode
Go to Troubleshoot > Advanced options
Select Command Prompt to restart Windows with the console environment
Pick your user account and set the correct password

Write these commands and press Enter after each one:

```
bcdedit/deletevalue {default} numproc
```

bcdedit/deletevalue {default} truncatememory

Restart your PC and check results

11. Fix the BCD

If your BCD has missing, damaged, or modified data, it’s no wonder that your operating system won’t boot you to the desktop. However, you can repair BCD errors using Command Prompt and a Windows media installation disc.

Connect a disc or pen drive with the Windows media installation files to your PC
Start Windows in Advanced Startup
Access Troubleshoot > Advanced Options > Command Prompt
Enter the following commands (press Enter after each one):
- ```
bootrec /repairbcd
```
- ```
bootrec /osscan
```
- ```
bootrec /repairmbr
```
Reboot your computer

12. Repair hard disk errors

Hard disk failure is a common reason for Windows boot issues. But you can fix this problem without having to install third-party software applications, thanks to CHKDSK (Check Disk).

How to use CHKDSK:

Start Windows in troubleshooting mode
Go to Troubleshoot > Advanced Options > Command Prompt
Run chkdsk c: /f /r if Windows is installed on the C: drive. Otherwise, make sure to replace c: with the correct partition letter
After CHKDSK does its job, exit Command Prompt and try to boot Windows 10

13. Fix corrupt system files

When it comes to repairing corrupt system files, you can rely on SFC (System File Checker). Just like CHKDSK, you can operate SFC from Command Prompt. However, you need a Windows 10 installation media to fix damaged, missing or modified system files.

How to use SFC:

Connect a Windows installation media disk to your PC
In Advanced Startup mode, go to Troubleshoot > Advanced Options
Select Command Prompt, pick your Windows account, and enter your password to continue
Type sfc /scannow and press Enter
Once SFC does its job, quit CMD and try to start Windows 10

If SFC doesn’t show any problems, you should use DISM (Deployment Image Servicing and Management) to check the component store of the OS image.

How to use DISM:

Make sure that a Windows installation media disk is attached to your computer
Boot Windows in troubleshooting mode
Access Troubleshoot > Advanced Options
Pick Command Prompt, select your account, and enter your password
Run DISM /online /cleanup-image /scanhealth
If DISM identifies any problems, repair them using DISM /online /cleanup-image /restorehealth
Reboot the computer and access Command Prompt again
Run SFC (sfc /scannow)
Try to boot Windows 10 now

14. Run ePSA Diagnostic on DELL

If you have a DELL desktop or laptop, you can turn to ePSA Diagnostic. It’s a special tool found in BIOS, which you can use to run hardware diagnostics without an OS and fix hard drive problems that might be causing Windows 10 boot issues. Here’s how to use it.

In Advanced Startup, go to Troubleshoot > Advanced options
Select UEFI Firmware Settings and click Restart
In BIOS, find and access the Diagnostics area
Deploy ePSA Diagnostic and follow the step-by-step instructions

15. Enable Legacy BIOS boot

Many users report that switching from UEFI to Legacy BIOS mode helped fix their boot problems on Windows 10. Here’s what you need to do:

In Advanced Startup, go to Troubleshoot > Advanced Options
Select UEFI Firmware Settings and click Restart
After booting to BIOS, locate the Boot area
Select UEFI/BIOS Boot Mode and press Enter
Enable Legacy BIOS Boot Mode
Save the current BIOS settings and exit

16. Disable Fast Boot

Fast Boot is a Windows 10 feature designed to start your operating faster by pre-loading drivers. However, if you have recently installed a Windows update that conflicts with Fast Boot, this could lead to boot problems on Windows 10.

To fix this issue, you should disable Fast Boot:

In Advanced Startup, select Troubleshoot > Advanced Options
Go to UEFI Firmware Settings and click Restart
In BIOS, find and access advanced settings
Disable Fast Boot
Save the current BIOS configuration and exit

17. Reset BIOS

If you have changed BIOS settings without exactly knowing what you’re doing, you might have inadvertently triggered boot problems, preventing your computer from starting your operating system.

But you can resolve this matter by restoring BIOS to factory values:

Boot your PC in Advanced Startup mode
Go to Troubleshoot > Advanced Options > UEFI Firmware Settings
Click Restart
Once you access BIOS setup, enable the option that resets the BIOS configuration to default
Save changes and exit

18. Update BIOS

BIOS needs to be updated, just like your operating system and applications. It you have rarely or never done this, you shouldn’t postpone the task any longer. However, for this solution, you need to use another computer to download and copy the BIOS installation files.

Boot Windows in troubleshooting mode
Select Troubleshoot > Advanced Options > UEFI Firmware Settings
Click Restart
In the main section of BIOS, check out the BIOS manufacturer, current version, and install date
Connect an USB flash drive to another computer
Visit the website of the BIOS manufacturer
Find and download the latest BIOS version
Unzip the downloaded archive to the pen drive
Unplug the pen device and connect it to your PC
In BIOS setup mode, create a backup of the current BIOS configuration
Then, start the BIOS update
Once the update is complete, try to boot Windows 10

19. Repair the system registry

The Windows registry might have missing, corrupt, or changed entries that are essential for the system’s runtime. It could be the reason why Windows 10 won’t boot anymore. In this case, you can use a registry cleaner or, if you don’t have to install any third-party tools, check out the steps below.

How to fix registry settings using Command Prompt:

In Advanced Startup mode, go to Troubleshoot > Advanced Options
Launch Command Prompt
Select your account and enter your password to continue

Enter the following commands (press Enter after each one):

```
cd c:\Windows\System32\config
```

ren c:\Windows\System32\config\DEFAULT DEFAULT.old

ren c:\Windows\System32\config\SAM SAM.old

ren c:\Windows\System32\config\SECURITY SECURITY.old

ren c:\Windows\System32\config\SOFTWARE SOFTWARE.old

ren c:\Windows\System32\config\SYSTEM SYSTEM.old

copy c:\Windows\System32\config\RegBack\DEFAULT c:\Windows\System32\config\

copy c:\Windows\System32\config\RegBack\DEFAULT c:\Windows\System32\config\

copy c:\Windows\System32\config\RegBack\SAM c:\Windows\System32\config\

copy c:\Windows\System32\config\RegBack\SECURITY c:\Windows\System32\config\

copy c:\Windows\System32\config\RegBack\SYSTEM c:\Windows\System32\config\

copy c:\Windows\System32\config\RegBack\SOFTWARE c:\Windows\System32\config\

Exit Command Prompt
Check if you can boot Windows now

20. Change drive letters

If you have two or more drives installed on your PC, you might experience Windows 10 boot errors if one of the partitions doesn’t have a drive letter assigned.

You can easily set drive letters using Command Prompt:

Boot Windows in troubleshooting mode
Visit Troubleshoot > Advanced Options
Open Command Prompt
Pick your PC account and set your password to confirm
Run diskpart
Enter list volume to view all drives and their letters
The Windows partition has Boot written at Info
Check if the Windows partition has a letter assigned
Otherwise, do the following
- Take note of the Volume # noted at the Windows drive
- Enter select volume # and replace # with the correct volume letter (e.g. select volume 0)
- Write assign letter= and add the drive letter you wish to assign (e.g. assign letter=c)
Exit Command Prompt and try to boot Windows now

21. Run a malware scan

If your computer was recently attacked, a malware agent could have hijacked critical system files that Windows 10 needs for the boot sequence. So it’s a good idea to scan your PC for malware.

Normally, you use Windows Defender or a third-party antivirus tool for this job. However, since you can’t work your way around the boot issue, you need to look into alternative solutions.

Here’s how to use Kaspersky Free Rescue Disk:

Download Kaspersky Free Rescue Disk from the official website
Burn the downloaded ISO image to a USB flash drive, CD or DVD
Connect the pen drive or disc to your computer
Boot your PC from the pen drive or disc
Update the antivirus database
Scan your system using Kaspersky Free Rescue Disk
Follow the step-by-step instructions

22. Use System Image Recovery

If you have previously copied your files and applications for safekeeping using Windows Backup, then you can use System Image Recovery to restore the backup and fix Windows boot problems. However, if you haven’t already done this, keep in mind that you can’t create a backup on another PC in order to restore it on the computer with boot problems – it just doesn’t work.

Interrupt the PC boot three times in a row
In Advanced Startup mode, visit Troubleshoot > Advanced Options
Open System Image Recovery and follow the instructions

23. Remove and reseat your hardware parts

Perhaps your RAM card, hard drive, or PCI-E cards are not properly connected to your device. To repair this, you can remove and reseat your hardware parts. It means taking your computer unit apart, removing the components from their slots, and then firmly putting them back in but without applying force.

24. Use a third-party boot repair tool

You can create a multiboot system rescue disk using third-party products, such as Boot Repair Disk. However, you need a second PC to download the application and put it on an external disk.

How to use Boot Repair Disk:

Visit the Boot Repair Disk download page
Depending on your OS architecture type, download the 32-bit or 64-bit ISO image
Burn the ISO to a CD, DVD, or USB flash drive
Plug the disc or drive into the PC with boot problems
Make sure to boot your PC from the external disk
Follow the on-screen instructions

25. Use System Restore

If System Restore mode is enabled on your PC and if you have created a restore point before you started having Windows boot problems, it’s a good idea to roll back your operating system to that checkpoint and undo all software modifications.

However, this means that all programs installed beyond the restore point will no longer exist, so you will have to set them up again.

How to use System Restore from boot:

In Advanced Startup, go to Troubleshoot > Advanced Options
Open System Restore
Choose a restore point from the list. Click Show more restore points if necessary. You can also click Scan for affected programs to see which applications you will have to reinstall
Click Next and follow the instructions

26. Reset Windows 10

Unfortunately, Microsoft often fails to restore Windows to a previous checkpoint. When you have exhausted all options on this list and still can’t get Windows 10 to boot, there’s nothing left except resetting Windows 10 to factory values. Don’t worry since your personal files won’t be deleted. Here’s how to make it happen:

Start Windows in Advanced Startup mode
Go to Troubleshoot > Advanced options
Click Reset this PC
Select Keep my files and follow the on-screen instructions

You can fix Windows boot errors

To review, if your Windows 10 PC won’t boot, try to fix this problem by unplugging external storage devices, checking your HDD, SSD and laptop battery, starting Windows 10 in Safe Mode, skipping the Windows 10 bootloader, checking your drivers, and temporarily disabling Driver Signature Enforcement.

Furthermore, you can uninstall recent software programs and malfunctioning system updates, repair startup errors, use the BCD command or fix BCD, solve hard disk failure and corrupt system files, run ePSA Diagnostic on DELL systems, enable Legacy BIOS boot, and disable Fast Boot.

It’s also a good idea to reset and update BIOS to the latest version, repair the system registry, change drive letters, scan your computer for malware, use System Image Recovery, remove and reseat your hardware components, use System Restore, or reset Windows 10 if everything else fails.

How did you manage to fix Windows 10 boot errors? Did we miss anything important? Let us know in the comments below.

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Elena Constantinescu

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