If you have two EFI partitions, Windows will stop looking once it finds the first one.
Which is actually a problem sometimes, as it will stop looking and use the first one it finds, even if it’s on different drive than windows.
Imagine installing windows on a machine with two drives. Drive A already has an OS and an EFI partition, so you install Windows to drive B.
Except Windows will still go ahead and drop the bootloader onto drive A. Potentially breaking the OS that’s there, plus setting up Windows in such a way that it requires drive A to boot. EVEN THOUGH THAT ISN’T WHERE YOU INSTALLED IT.
This is why guides tell you to install windows with only one drive connected. It’s the only way to ensure it puts the bootloader and OS on the same drive.
It does work.
If you have two EFI partitions, Windows will stop looking once it finds the first one.
Which is actually a problem sometimes, as it will stop looking and use the first one it finds, even if it’s on different drive than windows.
Imagine installing windows on a machine with two drives. Drive A already has an OS and an EFI partition, so you install Windows to drive B.
Except Windows will still go ahead and drop the bootloader onto drive A. Potentially breaking the OS that’s there, plus setting up Windows in such a way that it requires drive A to boot. EVEN THOUGH THAT ISN’T WHERE YOU INSTALLED IT.
This is why guides tell you to install windows with only one drive connected. It’s the only way to ensure it puts the bootloader and OS on the same drive.