Is there any freeware tool to get back data from a ext3 partition? I found one that needs to be installed in Windows. Any thing that can be installed in Linux itself, or booted independently?
The partition has been untouched, and the files also have not been erased, but presently I only see a lost+found folder. Probably a minor partition table error which can be rectified by using a backup stored somewhere on the drive.

Related question.
The problem was probably caused when using qparted in Knoppix. I was puzzled when gparted and qparted, both of which are present in Knoppix displayed different partition data. Qparted numbered the partitions sequentially, hda1 to hda10, while gparted listed them according to their date of creation with hda1 being the first created drive (which is how most Linux distros seem to do it). Unfortunately, Knoppix-installer used qparted, and resulted in the present problem. What is the best way to deal with similar situation, when two partition tools offer different information?

Could try gpart and testdisk for that second opinion.

Have a look at dd_rescue and check out all the dd options - the fact that you can only see lost+found does not bode well though.