How to Fix GRUB Not Showing in a Dual-Boot Setup
Dual-booting is an easy way to try Linux without giving up the convenience of Windows. Sometimes, however, you might run into troubles with the GRUB bootloader.
A rare but difficult-to-deal-with issue that dual-boot users may face is the GRUB bootloader menu not showing up during boot. Here's how you can fix this quickly.
1. Change the GRUB Boot Priority

Your system boots up with the topmost bootloader in the boot priority queue. Sometimes, the GRUB bootloader is somehow placed below the Windows Boot Manager. This does not show the GRUB bootloader and results in your PC booting up to Windows. Here's how you can fix this:
That's all the steps you need to follow to fix the GRUB bootloader not showing up due to a boot priority issue and restore your access to Linux.
2. Add Your Linux Installation to the Boot Menu
Sometimes, the Linux boot entry might not appear in the UEFI BIOS. This means your PC will boot with whatever option is left, which in most cases is Windows.
To fix this, manually add your Linux distribution to the boot entry by restarting your computer. As it boots up, press the F12 or Del key. This will take you to the UEFI BIOS control panel.
Look for Boot settings and click on Add New Entry. Locate the shimx64.efi file and confirm your changes. This should fix the GRUB bootloader not showing up issue and you should be able to easily boot with GRUB on a restart.
This method may or may not work for all computers. In case this doesn't work for you, try the alternative solutions.
3. Disable Windows Fast Boot
The Fast Startup feature in Windows 10 helps you restart your PC faster after shutdown. When enabled, it speeds up boot time by saving your operating system to a hibernation file.
A major disadvantage to this feature is that it often messes up dual-boot setups and might be the reason behind the GRUB bootloader menu not showing. Here's how you can disable this feature:

That's all you need to do to disable fast startup. Restart your PC, and you should be greeted by GRUB.
4. Use bcdedit to Set the Path for grubx64.efi/shimx64.efi
bcdedit is a Windows built-in command-line utility that helps with troubleshooting boot-related issues. You can use bcdedit to default to GRUB each time you boot by defining the path to the GRUB bootloader. Here are the steps to follow:
# Replace ubuntu with your distribution
bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi Modifying boot settings is dangerous, and you may end up breaking your system. So only use this solution as a last resort.
GRUB Not Showing Up? Use Windows Boot Manager!
GRUB bootloader can be troublesome to use at times. In case you cannot fix GRUB at all, try switching to Windows Boot Manager for a change.
You can boot into different distributions with the Windows Boot Manager, just like with GRUB. While it may not have all the features of GRUB, it does its job as a boot manager.
ncG1vNJzZmivp6x7rq3KnqysnZ%2Bbe6S7zGidorBdnL%2B2roynpq1lo528uLXNoGSipl2ZwqK4jJumqKxdqLK1wc9o