Thanks everybody for help.
I just have another question now.
I should reformat the whole hard disk after the recovery is done.
As experience shows,all people who had my problem were using NTFS format which Microsoft claims that it's the most secure and reliable format among the others.

It's hard to believe and I don't want to face the same failure, just because of using NTFS format on my hard Disk.

Microsoft also claims the largest portion of hard disk everybody can have by Fat32 is 32 GB.

I want to know if there is any way for me to format my hard disk by Fat32 and make one 300 GB partition .

Honestly,I don't want to use NTFS anymore.

Please recommend the best way I should choose.

Regards,
Android.

Ps:does anybody have PC3000 to share with me?