Thanks to all who responded to my delima. Unfortunately, everything I tried failed to get VISTA and XP to not display the error: "Network path not found."
I just about gave up when I came across something that worked. All I needed was to access each computer's files via the others. I found a "back door" entrance to both computers. Here's the situation: Both computers could "ping" each other by IP address only, not name. In each operating system, in the Run command from the Strart menu, I typed 2 backslashes "\\
" plus the IP address of the other computer. Magically, all the shared folders from the other computer displayed on the other computer!!! and vice versa. I was not able to copy over older files as I still received a nasty warning saying that "I did not have permission..." or something like that. To get around that, I just copied the files I needed from one computer to a different folder on the other computer (eliminating copying over the other folders and eliminating the warning). Then, I went to the other computer and just copied the files over the older ones and the replacement/updating of files was complete. It's a little bit of a hassel but it works (extend middle finger to Microsoft).
To this day, I don't understand how Microsoft can put out a product that does not work with previous versions OF THEIR OWN PRODUCT!!!!!! amazing.
Once again, thanks to all who helped. One last note: I can share printers by "browsing" the other computer when you want to print something, buy IP address and not name... Works like a charm.