I use an external harddisk to backup my data (it had 3 partitions). Last week when I plugged it in, the OS (Win 7) hung up and I had to force re-boot the machine.

When I turned it back on, the system just did not detect the hard-disk. It was last Sunday and I had to give up after sometime. Now I return back next Sunday (today) and when I plug it back-in to the machine, the OS detects the disk as well as all the 3 partitions on it. But it says all 3 are unformatted and I cant access any of them.

Is there any way to recover data from the 3 partitions (I tried PC File Recovery and Recuva from PiriForm but neither detected these partitions).