On 07/19/2014 11:24 PM, Eric Smith wrote:

I installed CentOS 7 on a Shuttle X27D box (dual-core Atom 330), and so far it seems to work fine, but it didn't set up a Grub2 entry for the existing Windows XP installation in the first partition (MBR). Running os-prober generates no output.

fdisk shows that the NTFS partition is still present as /dev/sda1, and still has the bootable flag set.

I added a menuentry for Windows to the end of /etc/grub.d/40_custom:

menuentry "Windows" { set root=(hd0,1) chainloader +1 }

and ran:

grub2-mkconfig >/boot/grub2/grub.cfg

and that lets me boot Windows, but I thought this was supposed to be taken care of automatically. Is there any known problem that prevents the installer or Grub2 from finding Windows XP?

I don't normally set up dual-boot on production machines, but I use it a lot for testing.

It does not see Windows 7 either.

Note that Windows 7 to boot might need :

menuentry "Windows 7" { insmod ntfs search --set=root --label WINDOWS_7 --hint hd0,msdos1 ntldr /bootmgr }

and that msdos1 parametar in GRUB2 does not start with 0 but with 1? (Check this)