if using dual-boot via grub2 and, after its installation windows (7,vista, xp...whatever) is missing from grub's menu, use this link to fix it:
http://blogs.koolwal.net/2008/12/28/windows-xpvista-dual-boot-does-not-boot-from-grub2-or-grub-pc/

or this cut out version:
create and edit the following file using your favourite editor, joe in this case:
sudo joe /etc/grub.d/11_Windows

containing text below:
#! /bin/sh -e
echo "Adding Windows" >&2
cat << EOF
menuentry "Windows Vista" {
set root=(hd0,1)
chainloader +1
}
EOF

set permission
sudo chmod a+x /etc/grub.d/11_Windows

update grub
sudo update-grub2

(reboot)