Recover file across a local network - urgent homework!

Hi all,

I'm searching through the various file recovery programs looking for something that is free and can look for deleted files across our network. My son has accidentally deleted both original and backup file. We have Recuva on that computer but I can't seem to figure out how to use it - I'm looking at the beginner's guide in their forum at the moment but in case I can't figure that out, does anyone know of a free program that I can use across the network to get at his machine to look for his file?

He deleted it and then emptied the Recycle bin.

Thanks people!

Edit: I've just tried using Recuva on this machine and it claims to have found lots of stuff but it won't let me choose particular file details, as far as I can figure out. Supposedly there's a help file but I can't access the online one and I can't find one on the computer. So definitely want help please! And I forgot to mention, Recuva on the machine with the lost file is claiming that there isn't anything to find.