Fixing GRUB error: unknown filesystem, grub rescue

If you have dual boot system ubuntu and windows  and you get this error unknown filesystem you would want to recover your windows first priority. You need to start your computer with extranal Ubuntu live CD or USB (if not sure see my other tutorial Creating a bootable USB stick… ).

once you run ubuntu then you need to open commandline (Ctrl + Alt + t) you need to be root to access root type:

sudo su

Then type following commands successively

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update && sudo apt-get install -y boot-repair && boot-repair

Once done will open the boot-repair windows with two options choose the first option ( need to be patient it will take time).Restart computer without the CD or USB and see if it fixes the problem if not then run you live ubuntu again and type’gksu boot-repair’ in the commandline. It will popup the window again and choose the second option. Restart and see if it fixes the problem if not follow the link here for further help.

  1. selvakumar says:

    i required the command of “grub rescue>” is asking and i am not having CD drive.Please help me?

  2. ateh says:

    it work with LuninuX OS 12.10

  3. Gerick says:

    i made a usb stick with ubuntu…. but, doesnt work….
    the laptop cannot boot from usb or CD/DVD….

    i think the grub is broken and lets not start any alternative boot

    when in grup rescue> ls
    show me all partition fine… for example ls(hd0,1), see my files but cannot boot for recovery or make fresh install

    please help

  4. hikmatune says:

    Hi Gerick,

    May I have your laptop model? Unless it is too old otherwise it should start with USB. You can go to BIOS and set the boot priority it is nothing to do with the Grup. Your computer should have the BIOS without the presence of an operating system.


  5. Dhanesh says:

    when i type the above commands it prompts an error that “Error : need a repository as argument” .. what to do now ..

    • hikmatune says:

      It usually happens if you run the two commands together.

      Try these three commends separately.

      sudo add-apt-repository ppa:yannubuntu/boot-repair

      sudo apt-get update

      sudo apt-get install -y boot-repair && boot-repair

      • hikmatune says:

        If still didn’t work you need to run this command:

        sudo apt-get install ppa-purge

        Then try the above again…

        Still no luck, let me what is your Ubuntu version.

  6. vish says:

    Hi hikmatune,
    i also has the same shows lik tis.

    error: unknown filesystem
    grub rescue >

    as i dont no anything abt linux pls help me in a easy way.. i dont hav a ubuntu in cd or usb drive could u pls tel me a simple way to solve tis problem????

  7. John Nash says:


    i also has the same shows like this.

    error: unknown filesystem
    grub rescue >

    But my problem is that i have formatted the hard disk which was hosting the ubuntu.

    pls I would like to know if what u suggestin to the others can work in my case or i need a diff


    Please i need your help. Thanks

    • hikmatune says:

      Hi John, If you have formatted the whole hard drive this will not work for you. In order to get important data from your formatted drive you would need to use recovery softwares like photorec. Otherwise you can freshly install new ubuntu. Hope I have answer you query.

  8. John Nash says:

    I cannot boot into my windows…so how can i use this photorec
    Also i have installed a new ubuntu on the hard disk but i am still getting the error still
    thank you

  9. Enrique says:

    great!!! thanks!! you save me!!!.. i was really worry, cause i installed recently my OS.. 🙂

  10. kishan says:

    same problem here. I have windows 7 and ubuntu 12.04

    error: unknown filesystem
    grub rescue>

    solutions are unsuccessful

    I have tried

    sudo add-apt-repository ppa:yannubuntu/boot-repair
    sudo apt-get update
    sudo apt-get install -y boot-repair && boot-repair && boot-repair

    but it does not work

    I have tried

    sudo apt-get install ppa-purge

    but does not work still

    please provide me a solution. My life depends on my laptop

  11. rylandiaz says:

    Thank you sooooooo much! you saved my computer 🙂

  12. Henfrey says:

    Am using windows 8 and linux and after partioning my hard disk thats when it started to ask about grub rescue and unknown file system…what do I do?

  13. kate says:

    thanks dear …
    its totally works for me…

    but got a Q for u …
    when i reboot, my pc run window 7 os …
    its not screen with dual boot menu …
    is that normal?
    if i reboot again, did the menu shows up?

    • hikmatune says:

      Hi Kate, If you read the description you will find this approach fixes Windows OS. You would require to re-install Linux OS. Thanks

  14. rishiraj says:

    I have Ubuntu installed on Win8. Ubuntu ran quite smoothly for few days, after which, it gave the ‘unknown file system grub rescue>’ error.
    Can you please tell me how to fix it?
    Note: I made seperate partition from Win8, ran Ubuntu from USB, and then installed in that partition.
    I also made all the necessary swap area/ root partitions.

    • hikmatune says:

      Hi rishiraj,

      Follow this tutorial you should be able to recover your Win8 and reinstall Ubuntu. You would need to create a bootable Ubuntu USB stick or CD click here. Once you create the USB or CD boot the computer from the USB/CD. You wouldn’t need to install Ubuntu again just start using the live Ubuntu and follow the instruction on this tutorial.

  15. hari says:

    grub loading welcome to grub error : unknown file system entering rescue mode. grub rescue
    plz help me this s recogzinsed for USB not CD Drive

    • hikmatune says:

      @hari do you have dual boot or just Ubuntu? You should be able to repair grub after creating a USB bootable Ubuntu disk click here. Once you run your computer using the newly created bootable USB stick type these commands in Terminal:

      sudo add-apt-repository ppa:yannubuntu/boot-repair
      sudo apt-get update
      sudo apt-get install boot-repair

      A windows will appear go to advance make sure Reinstall GRUB is selected. This should fix your Ubuntu. If everything fails you should be able to recover your files and reinstall Ubuntu.

  16. Vinay says:

    How much time does it take ? It has been more than 40minuts

  17. Safwan Yahiya says:

    Thank You Dude! Worked Perfectly for me.

  18. Gopala krishnan.B says:

    my laptop has dual boot, (windows 7 & linux). I have deleted the Linux os partition. on rebooting my system, Just getting the following commands

    Welcome to grub

    No such partition

    , i cant go further from that using the above commands.

    is there any other way?

  19. Rohan says:

    I am having the laptop given by UP govt. I deleted the volume from Windows 7 and made a new one.
    Now on restart its showing Unknown filesystem. grub rescue>
    Following your suggestion I started computer with LiveCD Ubuntu 11.10.
    Now the problem is that this LiveCD is showing :

    BusyBox v1.17.1 ………….
    (initramfs) mount : mounting /dev/loop0 on //filesystem.squashfs failed: Input/Output error
    Can not mount /dev/loop0 (/cdrom/casper/filesystem.squashfs) on //filesystem.squashfs

    Please Help !!!!!

    • hikmatune says:

      @Rohan It seems that your laptop does not support the new version of Ubuntu please try loading older version of Ubuntu on to the CD and try again. Click here for older versions of Ubuntu.

  20. shabeer piyars says:

    hi hikmatune,
    i was using LinuxMint 10 alongside of wondows7…now i cant access either windows or linux.

    i have the following problem in my Dell inspiron N4030n laptop. Error shown as below –
    error : unknown filesystem
    grab rescue> _

    how can i recover my windows7 since i have some important data’s in my pc.

  21. nagucool says:

    Even I got the same error…”unknown file system … > grub rescue>”…
    Simply insert ur windows 7 dvd and boot ur laptop from d dvd…..
    Then it asks weather u want to INSTALL or UPDATE.. click on install…
    And then a list of drives is displayed to ask on which drive u wanna install windows 7….
    Click on d drive u dint previously install windows 7 or ubuntu….
    Now the installation process will begin…
    Once the installation is complete , restart ur system…… there will be a prompt asking u to choose ur operating system at the beginning I.e at boot time…. then choose whichever o.s u require……..!

  22. Pranav says:

    Thanks worked for me

  23. Chinmoyee says:


    I also have a similar issue, have gone through your post and done said installation completed but i am back with the same grub rescue prompt.
    Actually i have windows 8 and ubuntu12.04 dual boot and I was trying to upgrade to windows 8.1
    Please help…

    • hikmatune says:

      It only works with grub if you were using LILO or other boot loader it will not work. Make sure you go through all the information provided in the post I have given second option and finally referred reader to Ubuntu Boot-repair website. If there is a specific error message I will be able to help but if you are not getting anything I would say you are doing something wrong.

  24. pooja says:

    I am getting an error for “ppa” what should i do?

    • hikmatune says:

      @pooja Please provide more information I can’t help if I don’t know how are you getting this error. Check your internet connection. You would need internet connection to download the required packages.

  25. utkarsha says:

    cannot add ppa.Please check name or format is correct. I am getting this error please help
    Thanks in advance

    • hikmatune says:

      @utkaarsh When does the error happen? What live distribution of Linux are you using? Check you are connected to the internet and you can run apt-get update without any error.

  26. rajat says:

    in laptop its show unknown sudo. then wht i do?

    • hikmatune says:

      @Rajat if you are running live Ubuntu from a flash drive the command “sudo su” shouldn’t throw an error. What Linux distribution are you using?

  27. Sandeep says:

    Thank You… It worked for me…

  28. shiva says:

    Please send information in error.unknow file system

  29. KKumar says:

    Does the above process works for Linux Mint 16 along side with Windows 8 on a Lenovo U510 model aswell?

  30. sathesh says:

    i have windows 7 error:unknown filesystem entering rescue mode what i do plz plz plz tell me

  31. Avi says:

    I am trying to install Ubuntu 12.5 LTS version in Apple Mac Pro Workstation. It is not installed. It shows only blink message on screen. Pls send information for the same.


  32. sandip says:

    can you have another command that not giving any error like (if i write sudo comm. the nit gives error–> unknown command ‘sudo’)….

    • hikmatune says:

      @sandip I am not sure what are you trying to do. If you type “sudo su” will log you in as root you wouldn’t need to type sudo any more, if this is what you would like!

  33. Abhijit Borade says:

    thanx dear… it really worked… but there is no need to get updates… i did it without getting updates…

  34. Ronak Porja says:

    i have a problém while installing windows xp from pendrive ……the problém is when i restart to install then it shows ‘bootmgr is missing’ press ctrl alt del to restart and when i do that it restarts and shows CRUB_ and after that i cannot continue to install ……..what is the problém and what should i do……..pls pls pls pls pls help mě pls…….

    • hikmatune says:

      @Ronak Porja your pendrive may not be bootable use (winflash utility to create windows bootable pendrive). Also please make sure you have setup the system to boot from the pendrive first usually you can press F12 when the system boots up.

  35. Dan says:

    Not sure if this thread is still active..but here’s hoping.

    Basically, I had Win XP and Linux Mint Maya installed on my Toshiba Laptop and both were working fine until yesterday, when I tampered with the partition setup by mistake, resulting in my corrupting the Grub loader program.

    Now I’m getting the same “Grub error: unknown filesystem” message as everyone else here.

    I’ve followed the steps you’ve listed here to the letter, but nothing seems to work. I’m currently getting the following..

    “it@it:~$ gksu boot-repair
    The program ‘gksu’ is currently not installed. You can install it by typing:
    sudo apt-get install gksu
    it@it:~$ sudo apt-get install gksu
    Reading package lists… Done
    Building dependency tree
    Reading state information… Done
    E: Unable to locate package gksu
    it@it:~$ sudo apt-get install ppa-purge
    Reading package lists… Done
    Building dependency tree
    Reading state information… Done
    E: Unable to locate package ppa-purge
    it@it:~$ sudo apt-get update
    Ign cdrom://It saucy InRelease
    Ign cdrom://It saucy/main Translation-en_US
    Ign cdrom://It saucy/main Translation-en
    Ign cdrom://It saucy/restricted Translation-en_US
    Ign cdrom://It saucy/restricted Translation-en
    Ign saucy InRelease
    Ign saucy-security InRelease
    Ign saucy-updates InRelease
    Get:1 saucy-security Release.gpg [933 B]
    Get:2 saucy Release.gpg [933 B]
    Get:3 saucy-security Release [49.6 kB]
    Get:4 saucy-updates Release.gpg [933 B]
    Get:5 saucy Release [49.6 kB]
    Get:6 saucy-security/main i386 Packages [110 kB]
    Get:7 saucy-updates Release [49.6 kB]
    Get:8 saucy/main i386 Packages [1,238 kB]
    Get:9 saucy-security/restricted i386 Packages [14 B]
    Get:10 saucy-security/main Translation-en [61.0 kB]
    Get:11 saucy-security/restricted Translation-en [14 B]
    Ign saucy-security/main Translation-en_US
    Ign saucy-security/restricted Translation-en_US
    Get:12 saucy/restricted i386 Packages [9,688 B]
    Get:13 saucy/main Translation-en [711 kB]
    Get:14 saucy/restricted Translation-en [2,686 B]
    Get:15 saucy-updates/main i386 Packages [229 kB]
    Get:16 saucy-updates/restricted i386 Packages [14 B]
    Get:17 saucy-updates/main Translation-en [110 kB]
    Get:18 saucy-updates/restricted Translation-en [14 B]
    Ign saucy/main Translation-en_US
    Ign saucy/restricted Translation-en_US
    Ign saucy-updates/main Translation-en_US
    Ign saucy-updates/restricted Translation-en_US
    Fetched 2,623 kB in 19s (136 kB/s)
    Reading package lists… Done
    it@it:~$ sudo apt-get install -y boot-repair &&boot-repair
    Reading package lists… Done
    Building dependency tree
    Reading state information… Done
    E: Unable to locate package boot-repair

    Any advice or help you can offer would be really appreciated.


    • hikmatune says:

      @Dan sorry for the delay. You have to first add the repository. You are missing the first command “sudo add-apt-repository ppa:yannubuntu/boot-repair”. Just Use sudo don’t need to install gksu if you have sudo available.

  36. dhruv says:

    I have the problem when i am trying to boot from the cd it’s still showing the same error unknown file system even after setting it to boot first cd. I am having only one os! Plz help

  37. dhruv says:

    i am having ubuntu 14.04

  38. dhruv says:

    i got a better solution first download boot repair disk and run the run the repair.durung repair go to that partition manager and unallocate in then create a new partition (single one) then boot the windows wirh usb -recommended then enjoy

  39. Vaibhav says:

    Awesome. You saved my life. Zillion thanks to you .

  40. Ankush says:

    thanks dude. It helped me

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    It’s pretty worth enough for me. Personally, if all web owners and
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    will be much more useful than ever before.

  42. Anand kumar says:

    hi i’am using windows 8.1 and ubuntu it shows unknown file system, grub rescue and when i ran it using bootable device and type the following command sudo add-apt-repository ppa:yannubuntu/boot-repair, then it shows cannot add ppa: ‘ppa:yannubuntu/boot-repair
    please check that ppa name or format is correct

    • hikmatune says:

      Hi Anand,
      After the first command sudo add-apt-repository ppa:yannubuntu/boot-repair run sudo apt-get update. If still doesn’t work then you need to edit file in your favorite editor vi /etc/apt/source.list.d/yannubuntu-boot-repair-saucy.list and add this line of code deb saucy main (Note you can change the release name according to your Ubuntu version e.g. raring, quantal, precise but not Trusty(package doesn’t exist yet)) . Then save the file and run sudo apt-get update. Please let me know if still not able to fix.

      • Rakesh says:

        Hi Hikmatune,
        I installed ubuntu(This installation also in the previous ubuntu drive only )rather than using live ubuntu using usb. There are no files are deleted from win8.

        Now it was directly opening ubuntu but not windows 8 without showing GRUB. Give me the best way to get my genuine windows back.
        Please, thanks in advance and waiting for ur reply.

  43. bravensmart says:

    its showin
    W: Failed to fetch 404 Not Found

    E: Some index files failed to download. They have been ignored, or old ones used instead.

    while executing third command…..can anybody help me….its urgent thankz in advance

    • hikmatune says:

      Hi bravensmart, Please see my reply to Anand above. Thanks

      • Rakesh says:

        Hi Hikmatune,
        I installed ubuntu(This installation also in the previous ubuntu drive only )rather than using live ubuntu using usb. There are no files are deleted from win8.

        Now it was directly opening ubuntu but not windows 8 without showing GRUB. Give me the best way to get my genuine windows back.
        Please, thanks in advance and waiting for ur reply.

  44. Shashank rawat says:

    Hey I’ve this problem of unknown filesystem while I am booting my pc . It enters in a grub rescue mode. Then I type the commands
    set prefix= ( hd0,msdos9)/boot/grub
    set root=(hd0,msdos9)/boot/grub
    insmod normal
    After typing these commands it boots normally but on rebooting it again enter into rescue mode. I am not able to solve it permanently. Can you help me.? I have a dual boot of linux kali and windows 8.
    Plz help me out.

  45. Arun Degaonkar says:

    it worked perfectly for me on windows 8.1 Acer Laptop, ubuntu 14.01, need internet connection on. Restored windows system…
    Thanks a lott

  46. Shardul says:

    i have tried the apt-get method, but then it shows :
    “dpkg: error processing package man-db (–configure):
    subprocess installed post-installation script returned error exit status 1”
    it shows a dpkg error.

    I have windows 7 and I installed ubuntu 14.04 “alongside” my windows; it made a separate drive.

  47. Eliismiiley says:

    Hey guys!
    I run Windows 7 and wanted to install Ubuntu precise 12.04 as second OS. And later on, I found out I had 4 partitions instead of 2. Obviously made a mistake when partitioning the drive. I used the disk manager to delete the unused partition. I restarted the laptop and BAM! The grub rescue problem. I tried all thee solutions listed above, nothing solved the problem. Then I thought about reinstalling my Ubuntu OS, and everything is fine now. Both windows and Ubuntu boot the right way now. Luckily I didn’t have no files in Ubuntu so all my data has not been affected.
    Hope this will help you guys.

  48. […] Fixing GRUB error: unknown filesystem, grub rescue | Hikmatune – Hi, I have the same problem. With ubuntu installed on USB, not boot, black screen remains. And if you just boot from the disc appears “grub rescue>”… […]

  49. colonel says:

    I dint have a dual boot I only had Ubuntu installed now I wanted to remove the ubuntu and install windows 7 but the grub loading error 17 keeps on showing up not allowing the alset up to continue

  50. James says:

    my computer hd is in read only file system and when i boot using a usb-live cd its unable to mount the internal hd and I am stuck at grub rescue

  51. Jasmin says:

    I install duel boot Ubuntu 14.04 and windows 7 unfortunately I formet the drive which located Ubuntu and got an error :unknown file system entering a rescue mode .and I lost my bios password so I cant setting bios can I back windows 7 or Ubuntu ?plz help me

  52. BarryDC says:

    Thank you, buddy. It worked just fine 🙂

  53. Yeah says:

    Thank you very much. You save me!!!

  54. atharv says:

    hey it shows me
    root@ubuntu:/home/ubuntu# sudo apt-get install -y boot-repair && boot-repair
    Reading package lists… Done
    Building dependency tree
    Reading state information… Done
    E: Unable to locate package boot-repair

    plz help me its argent

  55. Sidan says:

    I do I fix that when I switch on my system which was having both win 7 and Ubuntu and now it shows that Error unknown file system

  56. Adharsh m says:

    i am getting the error unknown file system grub risk.
    i have a bootable windows 7 pendrive .i tried to install it .but the only getting the windows logo. . .plese help ,

  57. Gayathri says:

    Hello sir i have the windows 7 govt laptop i delete the linux and another one os but i dont know what is it and after open my laptop i cant open to do the process which shows that the grub error what can i do?pls give the solution sir and my laptop doesnt have the option of any cd port

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