Multiple windows in one disk using grub

https://help.ubuntu.com/community/GrubHowto#More%20information

title windows
  hide (hd0,1)
  unhide (hd0,0)
  root (hd0,0)
  makeactive
  chainloader +1

title windows_2
  hide (hd0,0)
  unhide (hd0,1)
  root (hd0,1)
  makeactive
  chainloader +1

source: http://en.opensuse.org/SDB:Booting_Multiple_Windows_Installations_from_One_Hard_Disk