You don't. At least not from within Word.
If you want to be able to use your documents, when working with in Word, act
as if your floppy drive does not exist. (This applies to CDRW/CDR drives as
well.)
Don't use Word to:
Open a document on a floppy
Print a document on a floppy
Edit a document on a floppy
Save a document to a floppy (not even a copy)
Word regularly trashes documents on floppy drives!
Instead, work on the document using your hard drive. Copy it back and forth
using Windows.
I know that for some with shared computers (libraries) this is a tough
prescription. All I can recommend for that is to use a brand new formatted
disk each time you save and don't do any editing.