Recovering information from a harddrive?

Tiddlypeeps

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May 28, 2011
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Important documents went missing from my dad's harddrive about a week ago. They seem to have just vanished, I can't really make any sense of it.

I have tried running a program that recovers deleted files from a HD. I thralled through the list of thousands of files and couldn't find a single one of the files that went missing. There were hundreds of files in the folder that disappeared, I find it very hard to believe that every single one of them have been overwritten on the HD in that small space of time. Especially considering the computer would have been used very little in that week. I managed to find some documents he would have deleted himself from months ago on the HD using that recovery program so I'm pretty sure the program works the way it's supposed to.

The only logical conclusion I can come up with is that the files were removed using a shredder, removing all trace of them from the HD. But I can't see anyone that would have access to the computer doing that, or even having the technical know how to even think of it.

Anyone any ideas how I can try find out what might have happened to these files?

Just for completeness he is using windows 7.