How to Repair Windows Bootloader Problems

How to Repair Windows Bootloader Problems

Here we can see, “How to Repair Windows Bootloader Problems”

If your Windows PC is throwing a mistake message at you before it even begins to load Windows, it’s possible that the boot sector on your system partition is broken, corrupted, or has missing files. Here’s the way to troubleshoot those problems.

What Are the Boot Sector and Master Boot Record?

The boot sector may be a small section at the start of a tough drive that gets created whenever you format the drive. The boot sector contains some code and data that helps BIOS control the startup process to Windows. The boot sector also hosts the Master Boot Record (MBR), which contains the disk signature, a partition table for the disk, and a little bit of code called the master boot code.

When a PC starts, the initial power-on routine is handled by the BIOS. The BIOS then loads the master boot code into the PC’s RAM and hands off the startup processes. The master boot code scans the partition table, determines the active partition, loads a replica of the boot sector into the PC’s RAM, and hands off the startup process to that code. It’s this bootstrapping process that permits the initial bits of the Windows code to start loading.

The boot sector can experience equivalent problems as the other a part of your hard drive—missing files, corrupted files, and even physical damage. When the boot loader process fails, it’ll happen after seeing the BIOS information but before Windows begins to load. You’ll usually see error messages just like the following:

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  • Error loading OS 
  • Missing OS 
  • Reboot and choose the proper boot device
  • Invalid partition table
  • Bootmgr is missing
  • FATAL: No bootable medium found! System halted.

If you see any of those messages, it means you won’t be ready to start Windows and can need to use the Windows Recovery Environment to try to do your troubleshooting. We’re here to steer you thru that.

Boot From the Windows Installation Media or Recovery Partition

The first thing you’ll get to do is start your PC into the Windows Recovery Environment. Your PC may feature a special recovery partition that will allow you to start the Windows Recovery Environment without having a physical disc. How you are doing that varies with what brand of PC you own, but you’ll often see a message during startup telling you what key to press to start recovery and repair. If your PC doesn’t have a recovery partition—or you’re just unsure how to access it—you can also start your PC by employing a DVD or USB with the Windows installer thereon.

If you don’t have an installation disc, you’ll need to use another PC to download a replica of Windows. You’ll then create a DVD or USB install disc that you can use else your PC. And by the way, if your PC remains operational, you would possibly want to require the precautionary step of making a recovery drive or system repair disc that you can use in the future.

  • If you begin your PC using an installation disc, click through until you see the initial Windows installation screen, then click the “Repair your computer” link rather than starting an installation. If you’re ranging from a recovery partition or repair disc, the screens might look a touch different, but you’ll find yourself at equivalent options we’re getting to cover here.
  • Windows will then load the recovery environment. On the primary page, click the “Troubleshoot” option.
  • The Advanced Options page will appear next, and it contains the choices we’ll be discussing within the next few sections.
  • Note that if you’re using Windows 7, the screens may look a touch different. You’ll see most of the equivalent options, though, including those we’re getting to cover next.

Repair Startup Automatically

  • In most cases, you ought to let Windows attempt to repair startup automatically. It will also plan to fix the Master Boot Record or recreate the boot sector, and it’ll scan for and check out to repair other common startup problems. On the Advanced Options page, click “Startup Repair.”
  • The next page displays all operating systems detected on your PC—even if you have one installed. Click the OS you would like to repair.
  • Windows will begin checking for startup problems and attempting repairs.
  • When the method is complete, Windows will allow you to know whether the repairs were successful. Either way, you’ll tend the choice to restart your PC or return to the Advanced Options page.
  • If Windows cannot automatically repair your PC, you’ll always try repairing the Master Boot Record or rebuilding the boot sector manually from the prompt. It’s unlikely it’ll work if the automated repair didn’t, since these commands are performed as a part of the automated repair process, but it won’t hurt to undertake.

Repair the Master Boot Record from the Command Prompt

  • If you favour handling things yourself—or an automatic repair failed—and you’re pretty sure that the matter is together with your Master Boot Record or boot sector, you’ll also drop to the prompt for a fast fix. On the Advanced Options page, click “Command Prompt.”
  • Once you’re at the prompt, you’ll be using the bootrec command, and there are a few options that will be useful in fixing bootloader errors.
  • To restore the Master Boot Record, type the subsequent command and hit Enter. This command writes a replacement Windows-compatible Master Boot Record (based on whatever version of Windows you’re using) to the boot sector without overwriting the prevailing partition table. It’s an honest start for repairing boot loader errors resulting from file corruption.
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bootrec /fixmbr

Type the subsequent command and hit Enter to write an entirely new boot sector to the system partition instead. This feature does overwrite the present partition table and thus can sometimes cause issues if you’re found out to multiple operating systems. After using this command, it won’t overwrite any data on your actual partitions, but you’ll get to reconfigure your multi-boot options. This command is beneficial once you suspect another OS installation or malware may overwrite your boot sector or if you think the boot sector itself is broken.

bootrec /fixboot

And in fact, the bootrec tool also offers other more advanced options. You’ll always type bootrec /? to ascertain more options for and obtain help with the command.

Windows 11/10 Boot Repair: Fix UEFI Boot Issue on Windows 11/10/8/7

Method 1. Use Startup Repair for Windows 11/10 Boot Repair

Windows Automatic Repair may be a built-in tool for users to use and check out to repair some standard errors on Windows PC. And you’ll also do this method to repair Windows 11, 10, 8 or 7 UEFI/EFI boot errors:

1. Boot Up Windows from Installation Media

  1. Insert Windows 11/10/8/7 installation disk or USB to your PC.
  2. Restart PC and boot from the disk or USB.

2. Enable Automatic Repair Option

  1. Click “Repair your computer” at the Install now screen.
  2. Click “Troubleshoot” at choosing an option screen > click “Automatic repair”.
  3. Choose an account from the list to continue at the automated Repair screen and await the method to end.

When the method completes, you’ll restart your PC, and then you ought to be ready to use your computer with no problems again.

Method 2. Use Diskpart to Fix UEFI Boot Error in Windows 11/10

If you’re a Windows 11/10 or 8 user and you favour free methods to repair UEFI boot error, you’ll follow below two solutions to unravel this issue now:

1. Enter Command Prompt from Advanced Options

  1. Insert Windows 11/10/8/7 installation disk or USB into PC > boot from the disk or USB.
  2. Click “Repair your computer” or hit F8 at the Install now screen.
  3. Click “Troubleshoot” > “Advanced options” > “Command Prompt”.

2. Run Diskpart to Set Partition ID and Assign a Drive Letter

  1. Type below command and hit Enter each time:
  • diskpart
  • list disk
  • select disk 0

2.When the message “Disk 0 is now the chosen disk” shows up, type list vol and hit Enter.

Diskpart will now show the complete list of volumes on your PC; find UEFI volume from the list: UEFI partitions will be on Volume 2.

3.Type below command and hit Enter each time: 

  • sel vol 2
  • set id=c12a7328-f81f-11d2-ba4b-00a0c93ec93b
  • Or SET ID=ebd0a0a2-b9e5-4433-87c0-68b6b72699c7

4.Assign the drive letter by typing the below command and click on Enter:

  • assign letter=G: (Note: G shall be a special drive letter which can’t be already used.)

3. Repair the Boot Record

1.Open prompt as an administrator, enter below command:

  • cd /d G:\EFI\Microsoft\Boot\ (Note: G is that the drive letter you signed to UEFI partition and remember to exchange G with UEFI’s partition letter)
  • Enter exit when the method completes.

2.To repair the Boot Record, open CMD and enter below command line:

  • bootrec /fixboot

Enter exit when the repair process completes.

4. Rebuild the BCD Store

1.Type each instruction and hit Enter each time:

  • ren BCD BCD.old
  • bcdboot C:\Windows /1 en-us /s G: /f ALL (Note: c:\ is the drive where Windows 11/10/8.1/8 is installed on.)

2.Type exit in the prompt when the method completes, then restart your PC.

Now UEFI boot is fixed, and Windows 11/10/8/7 are often boot abreast of your PC again.

Method 3. Change BIOS Settings

You need to pick the boot mode consistent with the sort of disk on your system. If you want to start an MBR system disk, you’ll select Legacy support rather than UEFI in boot mode. To start a GPT system disk, you would like to pick UEFI.

How to access BIOS: Common keys to enter the BIOS are F1, F2, F10, Delete, Esc, and key combinations like Ctrl + Alt + Esc or Ctrl + Alt + Delete, which are more common on older machines. You’ll enter the BIOS interface by holding down any of those keys while booting abreast of your computer.

Method 4. Add Disk Driver to Repair Windows 11/10 Boot

When you replace the RAID with a special machine or replace the first SATA or IDE disk with a more modern NVMe SSD, you’ll encounter problems beginning. You’ll use the subsequent Windows instruction to feature the driving force to the restored Windows image manually.

Dism /Image:X: /Add-Driver /Driver:”y:\z.inf”

Note: X: The disk character of the restored Windows boot partition, and in double-quotes is the location of the driving force. Inf file.

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Method 5. Change the SATA Mode for Windows 11/10 Startup Repair

After the older XP system restores, a blue screen or cycle start may occur; you’ll change to IDE mode to undertake to start.

If you run into boot problems after upgrading from an older HDD to a more modern SSD, check to ascertain if the BIOS is about else for AHCI. If you set it up for RAID mode, confirm the right RAID driver is added to the cloned system.


I hope you found this guide useful. If you’ve got any questions or comments, don’t hesitate to use the shape below. 

User Questions:

  1. Why is an automatic repair not working?

In some cases, Windows 10 Automatic Repair couldn’t repair your PC error are often caused by your disk drive, and therefore the only solution is to reconnect it. Just close up your PC, unplug it, open it, and disconnect your disk drive. Now you only got to reconnect your disk drive, connect the facility cable, and begin it again.

  1. Is Startup Repair Safe?

ESG team of PC security researchers strongly recommends removing Windows Startup Repair from your computer as soon as Windows Startup Repair is detected. An anti-malware tool that’s fully up so far should be ready to detect and take away any trace of a Windows Startup Repair infection.

  1. Will reinstalling Windows fix boot issues?

If, after trying all the above troubleshooting options, the Windows boot issues still occur, the simplest course of action is to reinstall Windows. A full Windows reinstall erases all files on the pc and reinstalls the OS.

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