Odd, I would have expected it to pick up Windows more than the others. In that case, follow these instructions to add it manually:http://www.linuxmint.com/wiki/index.php/Grub_2#Q_:_How_to_add_windows_entry_to_Grub_2_.3F
Change the value for "menuentry" to whatever you want to show up in the list and make sure you pick the correct drive and partition for where Windows' bootloader is. hd0 is equivalent to /dev/sda, hd1 is /dev/sdb, etc. hd0,0 would be sda1 (GRUB starts numbering at 0).