How to add Windows to GRUB

Question

I have my encrypted Archlinux installed on my SSD. Now I have one HDD with Windows installed. But in my GRUB just Archlinux is shown (no Wonder, because I just installed Windows on the other HDD, GRUB doesn't know of that by now.).

My Question is, how do I properly add my Windows-HDD to GRUB, so that I can choose which to boot when starting?

I am a little bit afraid of destroying my GRUB so I can't boot my encrypted Archlinux anymore.

Thanks!

Answer 1

Save a backup of your all your grub configuration files.

There are two methods I have used in the past:

1) Install ntfs-3g (which should allow your installation to see the windows partition automatically) using your package manager. It was available in the EPEL repo for me, but you'll have to find a different repo for it on Arch.

Then sudo grub2-mkconfig. This worked for me while trying to get my centos7 dual boot to work with windows.

2) Alternately, you'd be best off adding a custom entry by adding a file to /etc/grub.d/

For example, on my current system which is a Centos7 + Windows 10 dual boot:

$ sudo cat /etc/grub.d/40_custom
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
menuentry "Windows 10" {
   set root='(hd0,1)'
   chainloader +1
} 

Where the menuentry parameter is the name that will appear in the grub menu. The (hd0,1) will change depending on what hard disk and what partition you have windows on.