回复：还有一点，重要！！

There is no format option when I reinstall. I remember only 2 options, first time I chose repair xp. Second time, I chose the other one. After I tried recover system twice, I rebooted (maybe automatically rebooted during the recoveries, too)
I searched and found some software such as easyrecovery 6, getdataback and pcifilerecovery. Do you have any idea which one I should try first?