Score:0

How can i replace GRUB with the Windows 10 bootloader on UEFI?

cn flag

So i recently made a dual-boot with Ubuntu unity 20.04 And Windows 10 Pro, but I noticed that the bootloader has changed to GRUB.

I have seen tutorials on this topic, but they keep mention to change some stuff on MBR to work or using EasyBCD. The thing is, I'm on UEFI with GPT and EasyBCD doesnt support some stuff when you are on UEFI.

The reason im asking this is because i installed ubuntu and (possibly grub) on my external hdd and, removing the drive wouldnt allow me to boot to any os at all.

Btw I cant enable MBR or any other form of legacy stuff anywhere, so im pretty much stuck with UEFI.

cc flag
You can always change the boot order to put Windows first, you can always select which device/OS to boot with the EFI boot menu (some function key at power-up), and look at launchpad bug 1396379, (and do add yourself to the "Does this affect me" list) , which indicates no grub bootloaders at all were installed on your external hdd, but some necessary grub files are still there, so the hdd is required to boot at all.
galexite avatar
pk flag
You can re-order or even remove the Ubuntu entry from your system firmware's NVRAM using `efibootmgr`, to make Windows boot first. Running `sudo efibootmgr` shows you the boot options and their numbers. `sudo efibootmgr -o 0,1,2` changes the order to start with 0 first, then 1, then 2. `sudo efibootmgr -b 2 -B` deletes the boot option `2` (dangerous, of course!). You don't need the initial zeroes. Then, you can use EasyBCD to select `grubx64.efi` as an additional boot option in the Windows Boot Manager.
jimkoutso2008 avatar
cn flag
@galexite Thank you but how do you do the EasyBCD part? I want remind you that the things you can do in uefi mode is limited.
oldfred avatar
cn flag
Similar question: https://superuser.com/questions/1679313/how-to-move-grub-or-mbr-to-another-partition-on-dual-boot You just do not use EasyBCD with UEFI, its not required, if both installs are UEFI. But you may need grub installed to an external drive & then must have an ESP on that external drive.
galexite avatar
pk flag
@jimkoutso2008 You may not be able to do anything in your firmware's interface, but you can still use `efibootmgr`.
mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.