Well now that seems odd. It sounds as if the hard drive is dying. How old is the machine? If all the partitions got deleted then something went amiss. Sorry to say but it seems like there is gonna be no way to save the info on the drive.
That is unless you wanna remove the drive. Put it in another PC as a slave drive. Then remove all needed info.
Other than that i am sorry to say but it sounds like a format and a fresh install to me.