I installed Fedora on my computer by freeing up 20GB from the E drive in Windows 10 . But i realised that i didn't like the interface much , so i went back to windows disk management and noticed that 20GB of space was still free and so without deleting anything on it , i put all that space back into my E: drive on windows 10 . Now , after i restarted my computer , i got stuck on grub rescue which says Error : Unknown Filesystem . After some research on google , i found out that it was due to me deleting that linux partition which also deleted the grub bootloader which handled the booting of Windows and Linux . I found the following solutions to help me :

1)Repair the MBR bootloader which the Windows originally used by going into the command prompt using the Windows 10 bootable usb and putting in the command BootRec.exe /fixmbr .

The bootable windows 10 usb ends up getting stuck in the restart loop i.e. on the windows logo loading screen with the white dots moving in a circle .

2)Use a Ubuntu or any other Linux distro live usb and run gpart to format my HDD

I have tried to run/install Fedora , Ubuntu and Mint but they always get stuck in the process . Ubuntu always reports many errors like "Out of memory" "Kill process or sacrifice child" in a list whenever i try to "Try Ubuntu without installing" or "Install Ubuntu"

3)Use the following commands in the grub rescue terminal :

set boot=(hd0,msdos7)
set prefix=(hd0,msdos7)/boot/grub
insmod normal

This did get me to the grub menu which showed me the OS available on my HDD (Ubuntu and Windows 10) but whenever i clicked on Windows 10 , it got stuck in the restart loop i.e. at the windows logo loading screen and whenever i clicked on Ubuntu , it got stuck on a blank screen .

Please help .


You'll need a working windows 10 bootable USB drive/DVD. Use the official iso to generate these and they should boot. Once done, try bootrec /rebuildBcd from the recovery command prompt, along with bootrec /fixMbr

  • Like i said , i already have them and they work fine on my other laptop .But it just get stuck on the startup screen before i can even get to the "Repair Windows" button , on the affected laptop . – ResonateAlpha Mar 5 '16 at 14:50
  • Really weird, something doesn't add up...formatting a partition cannot cause out of memory problems. What is the RAM in your system? What are the errors you encounter while trying to run other live distributions? – Kartik Moudgil Mar 6 '16 at 5:24
  • I encountered same errors when trying to run Mint and Fedora . I have 6GB RAM – ResonateAlpha Mar 8 '16 at 6:59

I found the solution . Before , i realized that since i can't boot any OS like Ubuntu , Fedora , Windows , etc. using their boot images , i should try to format my HDD completely . But i couldn't format my HDD using any of the boot image programs like Active KillDisk , DBAN , Gpart etc. Then i came across Ultimate Boot CD and booted from that . Then i chose BOOTMGR ( Multi-Boot Manager ) program on it and selected my HDD on it . Then i selected 'Zap Disk' which 'Erases MBR and tracks 0 & 1" . Now , i simply reinstalled Windows using my Windows installation USB .
Note : This method deletes all the data on your HDD .

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.