Grub bootloader

I have just switched to Linux and made a clean install of Ubuntu 20.04 over Windows 10 (no dual boot). I want to skip the grub bootloader screen which appears at the startup. I have already gone through several posts which are written on this, but I still have the same issue. I have changed the grub config file and after changing it I saved the changes through a command as instructed.

Here is the config file.

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT="Ubuntu"
GRUB_TIMEOUT_STYLE="hidden"
GRUB_TIMEOUT="0"
GRUB_DISTRIBUTOR="`lsb_release -i -s 2> /dev/null || echo Debian`"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# 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 ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL="console"

# 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'
#GRUB_GFXMODE="640x480"

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

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

#GRUB_HIDDEN_TIMEOUT="0"
GRUB_DISABLE_OS_PROBER="true"
GRUB_SAVEDEFAULT="false"

export GRUB_COLOR_NORMAL="light-gray/magenta"
export GRUB_COLOR_HIGHLIGHT="black/black"

Summarizing what others wrote here:

You are about to shoot yourself in the foot. You need that menu in case something goes wrong; sooner or later that will happen. Don't attempt to get rid of the Grub menu completely; give yourself a chance to fix things in the worst case. It's okay to minimize the timeout to 2 seconds, but don't try to remove the menu completely.

Considering how long everything else takes at boot time (memory and hardware self-test etc., loading the kernel, initializing the system with all the various system services), those 2 seconds won't kill you; but not having the ability to fix your system by booting a previous kernel will.

Take this advice from someone who has been working with Linux since the late 1990s.

Also, from your comments it sounds as if you might not be aware that you need to run sudo update-grub after you edited that config file: Only then will the changes be propagated from /etc/default/grub which you edited to /boot/grub/grub.cfg which is generated from your configuration in /etc/default/grub plus kernels and other operating systems that are found (at that time) on your disks.

If your changes never seem to take effect, check where Grub is actually installed to; if you use the legacy MBR partitioning scheme, make sure you install it to the MBR of the disk you are booting from. If there is a previous install of Grub and your current one was installed to another boot sector, it might still boot your system, but any changes you make to your current Grub will only affect a Grub that is never used.

If you do that, please check the documentation exactly how to do it; it might be a dangerous operation.