I need to reinstall Windows 7 on Satellite C655. The laptop came with 5 discs, 3 of which I don't know what are for.There are three named Toshiba 1, Toshiba 2, Toshiba 3. Then another named Windows Recovery + (then weirdscribbling) Environment, and the other Toshiba apps and drivers. Is the Windows 7 on one of these? or do I have tobuy that with my own money?