i wanted to install Ubuntu 18.04 64-bit on my Microsoft Surface Pro 3. I tried to install it from my usb-stick created with UNetbootin.
When i try to install ubuntu, it gives me during the installation an grub-error.
I searched on the internet with bootloader-problems with the Surface Pro 3 and found many tips to repair the bootloader with the program "boot-repair".
But everytime i try to make a boot-repair, i get this error-message: Locked-ESP detected. You may want to retry after creating a /boot/efi partition (FAT32, 100MB~250MB, start of the disk, boot flag). This can be performed via tools such as gParted. Then select this partition via the [Separate /boot/efi partition:] option of [Boot Repair].
So i made these steps: I've created in the Ubuntu Live-Mode with gparted a FAT32-partition (size: 250MB) ahead of the ext4 ubuntu-partition and assigned the boot-flag to this partiton. After that i ran boot-repair again and selected the newly created partition as described in the error message.
But the error still comes, the grub-bootloader won't install. I also tried to set the checkbox in boot-repair on "Reinstall grub" and unchecked the checkbox with "Secure boot", but the error still comes.
I already disabled the "Secure Boot mode" in the UEFI and disabled hibernate in Windows.
I also found this thread in the internet: https://ubuntuforums.org/showthread.php?t=2112273 I followed the described steps in the thread and removed the file /EFI/ubuntu/grubx64.efi, but the error still comes.
I hope you guys can help me.
Additional info: I want to make my Surface Pro 3 dual-boot ready. I've currently installed Windows 10 but wanted to switch to Ubuntu as my main system with the option, to switch to Windows 10 for some things.