Solve ultimate case of grub rescue failure:
problems: 1.i386-pc not found****normal mode not working cp not working search.file not working. All can be solved by the following commands, Works with Ubuntu 18.04 also.
Step1: Find the root folder containing directory.
ls
For example, if the root folder is in (hd0, gpt4), then type
ls (hd0, 4)/
You will see some files or folders:
Now if you are lucky then do the following:
set root=(hd0, 4)
set prefix=(hd0, 4)/boot/grub/
insmode normal
normal
If you are lucky then it will solve your problem.
Sometimes people have problems like cannot find 1386-pc folder. In that case you have to look where is your grub folder. If you have a problem like:
In this case, you need to find the folder grub2. If you have grub2 and inside that folder you could have your i386-pc folder. Then you need to type
prefix=(hd0, 4)/grub2/
it will work.
If you do not have grub2 and could not locate i386-pc folder then do the following:
grub rescue>set root=(hd0, 4)
grub rescue>set prefix=(hd0, 4)/usr/lib/grub
grub rescue>insmode normal
grub rescue>normal
after executing this command your grub rescue mode will go to grub menu. Now you can execute the linux command.
linux comand
grub>set root =(hd0, 4)
grub>set prefix= (hd0, 4)/boot
grub>insmaod linux
grub>linux vmlinuz.....-generic
grub>intrd (hd0, 4)/boot/...-generic
grub>boot
It will bring you to the recovery mode. From there you can choose from the several available recovery options.
If it does not help then you need to download an ubuntu os, for example ubuntu 18.04. You can download from the following link:
ubuntu link
Make a bootable drive and open your computer with that live disk. It will not harm any of your documents. See a video on how to do that.
Now you have to find your i386-pc folder. It will be in
rootContainingDirectory-usr-lib-grub
Now copy i386-pc to boot/grub/ folder.
you may have a permission problem to overcome that type the following command:
sudo nautilus
Now right click on that directory and change owner to ubuntu live session user
follow the video: permission change
Now after you paste it in the boot/grub folder restart and remove the usb drive.
This time use the 1st set of commands, it will work. If the cp command is working then you can do this from grub menu also.