i was having the windows 7 then i install windows xp sp2. the windows xp hide the windows 7. now system boots only on windows xp. it does not show the option for operating system and start the windowx xp. now how could i get both the operating system without formating again. i have dual core with 2 gb ram and 250 gb sata with 4 partitions. windows 7 in c whereas windows xp in d.