Fix win 7 boot in CentOS

1. We can clearly see/boot/grub2/grub.cfg inside, said: Do not edit this file, this file is automatically generated by Grub2-mkconfig (of course you can also manually), modify this file although you can achieve the effect, However, after the system executes grub2-mkconfig, the configuration you modify will fail, which is obviously not good.


So the right approach should be:
You do Grub2-mkconfig-o/boot/grub2/grub.cfg first.
If you can get back Win7 or other system startup items, you won't have to do the following step,
If not, please modify the/etc/grub.d/40_custom, see figure.



Menuentry "Win7" {
Set root= (hd0,1)
Chainloader +1
}



After the modification, use the Grub2-mkconfig-o/boot/grub2/grub.cfg command to reconstruct the GRUB2 boot.

Fix win 7 boot in CentOS