Comment # 3 on bug 1047385 from Chris Ward

I looked around in the installation 'initramfs', and found
if [ -z "`which os-prober 2> /dev/null`" ] || [ -z "`which linux-boot-prober 2>
/dev/null`" ] ; then
  # missing os-prober and/or linux-boot-prober
  exit 0
fi
in /etc/grub.d/30_os-prober

There's no os-prober or linux-boot-prober in the initramfs. Does this account
for the missing setup of Windows booting from the installation ?