There are two options available to you which are very easy.
1. Linux Llve disk. This is just a live version of Linux on a bootable DVD. I like the Mint distro, other popular ones are Ubuntu and Debian. Boot from disk and just copy the files over on to your working HDD
2. Recuva. Is a tool designed for recovering deleted partitions and files, it can also recover non visible files like in your instance. It runs under Windows. This will take significantly longer than a live disk, and detect all of the deleted items on the disc, as well as the hidden items that you are looking for. Big administration job.