Being able to install and run Windows on your Mac can be very useful. Boot Camp Assistant makes this easy, but sometimes you might forget that the utility can also be used to delete your Windows installation. If you’ve manually deleted your Windows partition, you’re probably noticing that something called EFI Boot still shows up in your Mac’s boot manager. We don’t need that anymore, so let’s get rid of it. This procedure should work with all versions of OS X and macOS.
Proceed With Caution – This Procedure Can Render Your Mac Inoperable If You Aren’t Careful
Finding the EFI Partition
In order to delete the EFI Boot entry when you didn’t use Boot Camp Assistant to delete your Windows installation, you have to do some work in the Terminal. This procedure isn’t for the faint at heart, so be careful that you type everything properly.
First, you’ll need to locate the EFI partition, which is where your Mac stores information about what operating systems can be booted from your Mac. In the Terminal, type this command:
You’re looking for a partition on your main hard drive called EFI.
Once you find it, enter these commands one at a time:
sudo mkdir /Volumes/EFI
sudo mount -t msdos /dev/disk0s1 /Volumes/EFI
Replace /dev/disk0s1 with the correct partition you located using diskutil.
Deleting the Windows EFI Boot Entry
Once that’s done, you’ll need to navigate to the correct folder. Again in Terminal, type:
This will put you in the directory where your Mac stores information about what operating systems you have installed. You will likely see a folder called Microsoft. In my case, I also have folders called Ubuntu and refind, but I’m leaving those alone.
Delete the Windows EFI Boot entry by typing this into the Terminal:
rm -rf Microsoft
That’s it. When you restart your Mac, you shouldn’t get the extra EFI Boot entry any longer.