Just after formatting the hard drive it takes away the complete stored data from your hard disk. But the good news is that you can restore them. Only the possible way to recover the formatted data is using the file recovery tool on your hard drive. I have also tried the same to restore the lost files on it. Ask me to get the details of the software.
To tell the truth, the old data after format can be recoverable or irrecoverable. And that often depend on whether you have rewritten it by saving new data on the same drive.
If you have not, you do have a big chance to restore all your old data back with the help of a free hard drive recovery tool. This freeware is really worth a shot since it has saved all the data of my sister from a mistakenly formatted external drive. To download it here: http://www.freeware-fix.blogspot.com/2013/02/hard-drive...
But, if you have, part or all of your old data may be already gone. You should learn a lesion to back up your data all the time.
Hope my words work.