First of all, it is a quite risky operation, because it is almost impossible to recover them automatically. Nobody and no tool could guarantee that you wouldn't lose all your data. You'd better recover all your data to another HDD using recovery software like R-Studio or EasyRecovery, DataRecovery etc.
However if you still want to try and recover existing partitions:
- You need to determine the start and end points of your partitions using DataRecovery for example.
- Use WinHex - Physical Disc - Alt+F12 - Master Boot Record - Apply.
- Edit the data, Enter, close the window, Ctrl+S.
Be careful and good luck.