Well, the files I'm trying to edit originate on the Vista computer and I'm trying to open them from the XP.
When I messed with it a while ago, I was able to see the files, open the files, but not saved changes to the files. That's when I wrote my last post.
I went out and ran a few errands and returned, optimistic that I'd be able to solve this last piece of it.
Now, though, I can't even open the Vista files from the XP; Word "encounters a problem and must shut down".

Now it's asking for a password each attempt - when I was able to open the files, a password was not needed.
Here is what's most frustrating:
Nothing was done to the system that might have initiated these changes (password/no password, seeing/not seeing files, etc.). It is entirely illogical and thus, very difficult to pinpoint the problem.
How am I supposed to solve the problem if the rules keep changing? (rhetorical question, that)
Jon