All Files Deleted?

I am working on a friends PC (Vista Ultimate) that recently crashed (corupt registry reported when trying to boot). I pulled the HDD out and created an image before going any further. What I have noticed when bowsing the HDD (via another PC) is that almost all files i.e. ,pdf, .xls, .doc etc are gone. I did a search with pandora file recovery and can see them. My question is, is there some Malware out there that will delete your files but leave the folders and trash the registry? If so what is it so i can be more educated. I will be reinstalling from scratch seeing as how the PC will not boot even after repairs. Thanks

 

So could it be possible that the registry became corrupt due to bad sectors on the HDD. If so sounds like the HDD should be replaced. This is a new (3 months new) Dell with a 80 gig Raptor for the OS and a seagate for the data drive. I understand that even new hard ware can be defective. It was strange that it deleted all the files and left the folders even on the data drive. Thanks for the input>

 

The system would not boot and no repair attempted helped. So we had to reinstall.

 

I was able to recover most files on the data drive with Pandora Recovery, however getting the files especially .PST files from the system drive was not so successful. Thanks for your input.