Fix GRUB Loading Error 15, 17, 21, 22 and Recover Data

Jean updated on Feb 22, 2023 | Home >Computer Instruction

What Is GRUB

GRUB or GNU GRUB is short for GRand Unified Bootloader. It is a boot loader used on multi-OS computers that provides users the choice to choose which operating system to boot from on the computer. Different operating systems may need varying boot loaders. For example, NTLDR is the boot loader for Windows NT operating systems, and LILO is the boot loader for Linux. As for GRUB, it is the boot loader for Windows and Linux and is generally used on computers that are with both Windows and Linux installations.

Here's a quick view of common GRUB loading errors and corresponding solutions. Jump to the part you're most interested:

Workable Solutions Step-by-step Troubleshooting
Fix 1. GRUB Loading Error 15 boot from the Live CD, and mount/boot depending on your partition...Full steps
Fix 2. GRUB Loading Error 17 use a distribution CD or Live CD to set up Grub as sudo grub > root (hd0,0) > setup (hd0) exit...Full steps
Fix 3. GRUB Loading Error 21 Boot the computer from the Ubuntu installation disc > Run Command Prompt as an administrator...Full steps
Fix 4. GRUB Loading Error 22 Restart the computer and press "F8" until you see the options, go back to the menu...Full steps

Common GRUB Loading Errors

However, it's not without a problem while using GRUB. Many users have the experience of encountering the GRUB loading error during the computer startup. There are two versions of GRUB, and if you're using Stage 1.5 or Stage 2.0, you'll probably encounter grub loading error 15, 17, 21, or 22.

GRUB loading error 15

File not found. This error is displayed when the specified file name cannot be found.

GRUB loading error 17

Cannot mount selected partition. This error is displayed when the partition requested exists, but the file system type is not be recognized by GRUB.

GRUB loading error 21

The selected disk does not exist. This error is displayed if the disk is not recognized by the BIOS in the system.

GRUB loading error 22

No such partition. This error is displayed if a requested partition isn't on the selected disk.

What Causes GRUB Loading Error 15, 17, 21, 22

When you install Windows and Linux on a computer, you need to configure GRUB correctly to boot from one of the operating systems successfully. Or you may encounter GRUB loading errors, like error 15, 17, 21, and 22. The common GRUB loading errors might be caused by:

  • Improper configuration of GRUB
  • The wrong installation location of GRUB
  • Accidental deletion of GRUB
  • The corruption of MBR

How to Fix GRUB Loading Error 15, 17, 21, 22

The solutions differ based on the error you are faced with. Specify the error message you encounter and carry out the corresponding solution.

Fix GRUB Loading Error 15

Make sure the kernel exists. To find out what the exact kernel name is, boot from the Live CD, and mount /boot depending on your partition and then do the following: cd /boot | ls

Fix GRUB Loading Error 17

Make sure your root(x,y) settings are right in your Grub.conf. You could use a distribution CD or Live CD to set up Grub as shown below. (h0,0) means the first hard drive and the first partition on that drive.

sudo grub

root (hd0,0)

setup (hd0) exit

Fix GRUB Loading Error 21

Step 1. Boot the computer from the Ubuntu installation disc.

Step 2. Run Command Prompt as an administrator.

Step 3. Enter the following command:

$sudo -s
grub> find /boot/grub/stage1 (then cmd will return something like "hd0,0")
grub> root (hd0,0)
grub> setup (hd0)
grub> quit

Fix GRUB Loading Error 22

Step 1. Restart the computer and press "F8" until you see the options.

Step 2. Go back to the menu where you can choose the operating system.

Step 3. Choose "Microsoft Windows Recovery Console". (You may need your Windows installation disc to access the recovery console.)

Step 4. If you are asked to choose the system drive, enter the number in front of the system drive listed.

Step 5. Enter the account password as required. Run the command fixmbr and enter "y" to confirm the operation.

Step 6. Enter "exit" and restart the computer.

How to Recover Data Lost After Fixing GRUB Loading Error

Applies to: Restore all lost files and data after fixing GRUB loading error in Windows 10/8/7.

Applying the fix for a specific grub loading error in Windows may cause data loss. For example, some operations would format the disk partition or delete hard drive contents. So it's necessary to learn how to recover data after getting rid of the grub loading error on your computer.

Reliable EaseUS Data Recovery Wizard - EaseUS Data Recovery Wizard specializes in file recovery on all Windows operating systems. It allows you to recover data lost due to the GRUB loading error effectively in only a few simple clicks.

 Download for Win Recovery Rate 99.7%
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See how to recover the accidentally deleted or formatted hard disk data while fixing GRUB loading error on your computer with ease:

Note: To guarantee a high data recovery chance, install EaseUS data recovery software on another disk instead of the original disk where you lost files. 

Step 1. Launch EaseUS Data Recovery Wizard on your Windows 11, Windows 10, Windows 8, or Windows 7 computer. Select the disk partition or storage location where you lost data and click "Scan".

select the disk on Windows  to scan

Step 2. This recovery software will start scanning the disk to find all lost and deleted files. When the scan process completes, click "Filter" > "Type" to specify lost file types.

choose the recovered data type

Step 3. Preview and restore lost Windows files. You can double-click to preview the scanned files. Then, select the target data and click the "Recover" button to save them to another safe spot in the PC or an external storage device.

recover windows 10 lost data

Besides, you can also apply this data recovery software to recover files and data lost on the desktop, laptop, internal hard drive, external hard drive, removable USB flash disk, pen drive, memory card, and many more storage devices.

The Bottom Line

GRUB loading errors always occur on computers with dual OS, and each error code is informative since it indicates what the possible cause is. Apply the solutions provided to cope with the issue and use EaseUS Data Recovery Wizard to retrieve the data when data loss happens.

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Updated by Daisy

Daisy is the Senior editor of the writing team for EaseUS. She has been working in EaseUS for over ten years, starting from a technical writer to a team leader of the content group. As a professional author for over 10 years, she writes a lot to help people overcome their tech troubles.

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Written by Jean

Jean has been writing tech articles since she was graduated from university. She has been part of the EaseUS team for over 5 years. Her special focuses are data recovery, disk partitioning, data space optimization, data backup and Mac OS. By the way, she's an aviation fan!

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