This is a field that my company specializes in. I wrote a FAQ on this topic
. I do not sell my company's services here as that is not appropriate for this type of forum and my clients are typically from the legal community.
I have seen the results of highly skilled technicians trying to do a critical recovery on their own prior to sending it out, it makes the recovery harder, if not impossible for the professional company.
Note, if you want to use "free versions" of software be aware that not all functionality of tools like Paraben and FTK are available in their free versions. Compleatly read everything prior to using one. FTK (Forensic Tool Kit) does have a windows version.
To do this type of recovery, you must have another PC with a Write Blocker in between your HDD and the other computer bus or you will likely step on data in the process. If you download a tool to your PC, again you will likely step on the data in slack space.
The point I am making is that if you haven't done this before on a system that doesn't mean anything to you and this file is really important, use a professional.
If your file is not so critical, then yes try the free tools. You will gain experience and learn the limitations of the software.
Just another old goat