Undo "Grub Customizer" changes

Hi guys. Can someone tell me how to restore the original default grub?

Was having issues with tiny fonts on the grub screen so used "Grub Customizer" app to change the resolution to my computer's preferred grub resolution + added a bkg pic. Now, however, the grub screen flashes up (still tiny ) then the zorin loading png, then the background pic. So that customizer software messed it all up.

How do undo that and restore the original default grub? PS: I'm brand new to linux so my skills & know-how are minimal.

Reinstalling Grub will do it:Type this in terminal:

sudo grub-install /dev/sda
(or sdb, as case may be). Hit Enter. Enter password when prompted.

Do not specify partition, just device (that is, the hard drive, SSD, etc). If you only have one drive connected, it will be sda.

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Thank you so much for this @mdiemer .

I forgot to mention that I have a dual boot. Sorry! So, is it still safe to run that as is in terminal ? On install, I let Zorin install next to Windows. I didn't bother with creating partitions myself.

Yes, it will be fine.

Unfortunatly, that didn't work. I did it 2x and also added: sudo update-grub

The changes that "Grub Customizer" made are still there. Any other suggestions?

Can you run in terminal:

sudo nano /etc/default/grub

Then take Screenshots of the entire output? Post those here, so we can look over what is there and what is missing.
Keeping that terminal editor open, we can make necessary changes.

If you change this file, run 'update-grub' afterwards to update


For full documentation of the options in this file, see:

info -f grub -n 'Simple configuration'

GRUB_DISTRIBUTOR="lsb_release -i -s 2> /dev/null || echo Debian"

Uncomment to enable BadRAM filtering, modify to suit your needs

This works with Linux (no patch required) and with any kernel that obtains

the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)


Uncomment to disable graphical terminal (grub-pc only)


The resolution used on graphical terminal

note that you can use only modes which your graphic card supports via VBE

you can see them in real GRUB with the command `vbeinfo'


Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux


Uncomment to disable generation of recovery mode menu entries


Uncomment to get a beep at grub start

#GRUB_INIT_TUNE="480 440 1"


export GRUB_COLOR_NORMAL="light-gray/black"
export GRUB_COLOR_HIGHLIGHT="light-green/black"
export GRUB_MENU_PICTURE="/home/charlieg/Pictures/mcat.png"

Weird thing is... the resolution is not working and the pic shows up after booting into Zorin.

You can remove those...

Are you sure you want this? That's... extreme.

That is more than 4K resolution?

It's not extreme at all. It's the exact resolution of my screen and is what is recommended size in the $ videoinfo

I was hoping to just restore the grub to it's original state as I'd like to add a bkg image later. Whatever "Grub Customizer" did messed the grub up and they each load independently, first grub then image.

Is there an install script I can run in terminal to restore the original grub?

The suggestions I made above should get you to that.

I have a Dell xps 9700 - Ultra high definition, 3840x2400 in a 16:10 ratio... making everything rendered in 1920x1080 or less completely unreadable.

So happen to know how to reinstall original grub?

If you remove the /etc/default/grub file, then reinstall grub:

sudo apt install --reinstall grub

Please Do Not Reboot until you ensure that the new (default) grub file is in /etc/default/ and that you have run

sudo update-grub

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Thanks @Aravisian . That got it back to normal. Much appreciated.

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