Where do I install GRUB?
Where do I install GRUB?
You can dual boot both Windows 10 and Manjaro by adjusting your boot settings. Since you already have Windows 10 installed, consider removing its boot manager partition and setting it to point at the EFI system partition (usually /boot/efi). Alternatively, you could create a new mount point in /boot/efi for Manjaro. This approach keeps both OSes accessible without overwriting each other's installation.
Grub handles this automatically; the installer knows how to do it. Simply direct the installer to the location where you've set up Windows 10, and it will proceed.
It's not quite right to remove the Windows boot partition unless necessary. The outcome depends on whether you want Windows or Manjaro as the default, which determines which boot loader is written to the MBR. If you choose Windows as default, install Manjaro and follow these steps during recovery: write the boot sequence from Windows bootloader → GRUB → either Windows or Manjaro. If you pick Manjaro as default, simply install it and the process will prepare everything correctly.