This one is a keeper http://www.cgsecurity.org/wiki/TestDisk
I accidentally tried to install Ubuntu over my 500gb data disk. It deleted the NFTS partition then wrote its own ext4 file systems to the disk. Fortunately it died with an error then I realised my mistake.
The lovely folk over at expert sexchange referred me to this tool.
Downloaded… 3mb. Installed, 2 mins.
Ran it. It said “I found linux partition. Should I search deeper?” I said “yes please”.
Within moments it had found the NTFS partition so I stopped the scan. Said “recover that one please” so it did. In about 20 seconds.
Then it said “you need to reboot”.
Rebooted and voila! My disk is back! Yaaaaaay!