Find lost data. Disk Investigator.

Disk investigator is a free tool from Kevin Solway.

Disk Investigator helps you to discover all that is hidden on your computer hard disk. It can also help you to recover lost data. Display the true drive contents by bypassing the operating system and directly reading the raw drive sectors. View and search raw directories, files, clusters, and system sectors. Verify the effectiveness of file and disk wiping programs

It can also recover/undelete deleted files.

You get it here: http://www.theabsolute.net/sware/dskinv.html