Error 21 grub

error 21 grub

completions of a device/filename.] grub> setup --stage2=/boot/grub/stage2 --force-lba (hd0) (hd0,4) Error 21: Selected disk does not exist grub> quit. This error may occur because you are trying to boot into windows without the external/original drive attached. System optimization might resolve. Loading Error 21. The selected grub CD or DVD does not exist. This error is very common when the BIOS does not recognize the hard drive on some systems.

Apologise: Error 21 grub

Error 21 grub
Error 21 grub
Steam application load error p

Error 21 grub - join told


Hi Emi,


Thank you for posting your question on Windows Vista Forums.


The grub loading stage 1.5 Error 21” error seems to be specific to Ubuntu program.


I will recommend you to contact Ubuntu support as the techs from the Ubuntu support team should be able to help you fixing the above mentioned issue.

You may follow the given link to contact Ubuntu:



Ashish Gupta – Microsoft Support

Report abuse

Harassment is any behavior intended to disturb or upset a person or group of people. Threats include any threat of suicide, violence, or harm to another. Any content of an adult theme or inappropriate to a community web site. Any image, link, or discussion of nudity. Any behavior that is insulting, rude, vulgar, desecrating, or showing disrespect. Any behavior that appears to violate End user license agreements, including providing product keys or links to pirated software. Unsolicited bulk mail or bulk advertising. Any link to or advocacy of virus, spyware, malware, or phishing sites. Any other inappropriate content or behavior as defined by the Terms of Use or Code of Conduct. Any image, link, or discussion related to child pornography, child nudity, or other child abuse or exploitation.
Details (required):
250 characters remaining

Was this reply helpful?

Sorry this didn't help.

Great! Thanks for your feedback.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this reply?

Thanks for your feedback.

ls to check the exact name of the kernel file.

It is quite possible that the kernel file is missing from your computer. If so, you can still use the live CD to perform a system reinstallation to get rid of the issue.

How to Fix GRUB Loading Error 17?

If you are facing Grub Loading Error 17, you need to make sure that your root(x,y) settings are right in your Grub.conf. You still need to use a live CD to set up Grub as follows:

1. Boot your computer from a live CD.

2. Execute this command: sudo fdisk –l.

3. You are likely to get the following results:

Disk /dev/sdb: 500.1 GB, 500107862016 bytes

255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 4096 bytes

I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk identifier: 0x62ff371f

Device Boot Start End Blocks Id System

/dev/sdb1 2048 206847 102400 7 HPFS/NTFS/exFAT

/dev/sdb2 206848 174082047 86937600 7 HPFS/NTFS/exFAT

/dev/sdb3 174082110 976771071 401344481 f W95 Ext’d (LBA)

Partition table entries are not in disk order.

The cause of the problem appears on the last line: Partition table entries are not in disk order.

4. You can fix the problem by executing the following command: sudo fdisk /dev/hda. hda means the whole hard disk.

5. If you are an expert, you can select x and press Enter. If you are not an expert, just skip to the next step.

6. Select f and press Enter to fix the partition order.

7. Select w and press Enter to write table to disk.

8. Then, you need to finalize these command one by one in GRUB:

sudo grub

root (hd0,1)

setup (hd0)


Here, (h0, 1) stands for the first hard drive and the second partition on that drive.

Of course, the above hd0,1 and hd0 are just examples. You need to know which hard disk houses your OS and then replace the numbers according to your actual situations.

When all these steps are done, you can restart your computer to check whether it can work as normal.

How to Fix GRUB Loading Error 21/22?

If you are bothered by GRUB Loading Error 21/22, you can follow these steps to fix the problem.

  1. Boot your computer from the live CD.
  2. Open a terminal and then run sudo grub. This can lead you to a GRUB command line.
  3. Run find /boot/grub/stage1.
  4. Then, run root (hd0, 1). Here, (h0, 1) stands for the first hard drive and the second partition on that drive. You can replace these two numbers according to your own situation.
  5. Next, run setup (hd0).
  6. At last, run quit to complete the operation.

After these 6 steps, you still need to reboot your computer to see whether the GRUB Loading Error 21 or GRUB Loading Error 22 is disappeared.

If You Lose Your Data Due to GRUB Loading Errors

After the GRUB Loading Errors are solved, you can use your computer as usual. However, you may find that some important files are missing from your device by accident due to the error. In a situation like this, you can use a professional data recovery software to get back your data. Here, we suggest using MiniTool Power Data Recovery.

This free file recovery tool is specially designed to rescue your lost and deleted files from your computer hard drives, SD cards, memory cards, pen drives, CDs, DVDs, and more. It has 4 recovery modules that are designed for different situations.

For example, if you want to recover data from a partition on the hard drive, you can use the This PC module. But, if you have repartitioned the hard drive after missing files, you’d better use the Hard Disk Drive module because it enables you to scan the entire drive at once.

This software is designed for Windows computers. However, if your computer is dual-boot (Windows and Linux), you can choose to recover your Linux data under Windows.

MiniTool Power Data Recovery has a trial edition and you can use it to scan the drive that has saved your lost files and then check whether it can find the files you want to restore. If you are interested in it, you can press the following button to download and then install it on your computer to have a try.

Free Download

After installing MiniTool Power Data Recovery on your device, you can use these steps to retrieve your data.

1. Open this software and you will enter the This PC interface directly.

2. Suppose that you want to recover data from a partition, you can just stay at this recovery module. Then, you need to select the target partition and press Scan to start the scanning process.

select the target partition to scan

3. The whole scanning process will last for a while. To make sure that you can get the best data recovery effect, you need to wait until the whole process ends. Then, this software will show you the scan results by path.

Here, you can click each path and unfold the folders in it to find your needed files. However, you may find that it is not easy and fast to find the target items using this method. If so, you can use other features of this software to perform a quick search.

For example:

  • Type: The Type feature can enable the software to show the scan results by type. You must know which type of data you want to recover. So, you can select that type to find your needed files quickly.
  • Show Lost Files: After scanning, this software will show you all the data on the drive including existing and deleted files. If you only need to restore the deleted files, you can use this feature to make the software only show you the lost files. This can narrow down the search range.
  • Find: If you still remember the name of the file you want to recover, you can use this feature to directly locate that file. However, if the name of the file is damaged, you will be unable to use this method to find your data.
  • Preview: This feature enables you to preview up to 70 types of files. So, if you are not sure whether it is the file you want to restore, you can just preview it to make a confirmation.
Type, Show Lost Files, Find, and Preview

4. You are not allowed to use this trial edition to recover the scanned files. However, you can update this software to a full edition and then recover your needed files without limits. If you are a personal user, the Personal Ultimate edition can fully meet your need and you can even enjoy a lifetime free update.

Here, you need to know that you should not select the files’ original path to save these data. Otherwise, the deleted files will be overwritten and become unrecoverable.

Bottom Line

Now, you should know what GRUB is, the GRUB Loading Errors you may encounter when booting your PC, and how to get rid of these errors. At the same time, we also recommend a data recovery software for recovering your lost and deleted files that are caused by these GRUB Loading Errors. We hope this article is helpful to you.

Should you have any related issues, you can contact us via [email protected] or let us know in the comment.

GRUB Loading Error FAQ

What is a GRUB Loading Error?

A GRUB Loading Error always happens when you boot the computer. It can be caused by improper GRUB configuration, a wrong location of GRUS, missing GRUB, corrupted MBR, etc.

How do I fix grub loading errors?

There are different kinds of GRUB Loading Errors like GRUB Loading Error 15, 17, 21, and 22. This current article shows you the corresponding solutions. You can scroll up to find them.

About The Author


StellaFollow us

Position: Columnist

Stella has been working in MiniTool Software as an English Editor for more than 4 years. Her articles mainly cover the fields of data recovery including storage media data recovery and phone data recovery, YouTube videos download, partition management, and video conversions.

User Comments :