Digital BW, The Print

Lately I have encoutered a problem when trying to open my raw files. 
They are downloaded to my computer's hard disk using microsoft option 
to option to download. I place them in my work file on the hard disk.  
However, when I try to open the file with CS3, I am told the file 
cannot be opened because IT IS NOT THE RIGHT KIND OF DOCUMENT. Adobe 
Bridge CS3, is also unable to see the files. The files are in a raw and 
fine Jpg format and my operating system is Windows XP and my camera is 
Nikon D70.  I had initially had that problem with CS2 and I understand 
raw files would not be opened by this program. At that time, CS3 would 
open those same files.  Now I am confronted with the same problem with 
CS3.  Could someone help me get out of this predicament?
Please.

Bob