How do I recognize and remove backed up files, so I may
free additional disk space. Any help or advice would
appreciated. Thank you in advance for your time

Tipically, they lack archive attribute. (This only works if backup is
"normal" or "incremental", not "Copy").

You could start by setting the whole disk to +a (archive) and then do a
backup. All files that don't have the Archive bit set were backed up. You
will most likely do this by hand (check properties) or with a script. XCopy
might also help in the task.

--
Andrei "Ndi" Dobrin
Brainbench MVP
www.Brainbench.com