I think perhaps you are referring to the MRU (Most Recently Used) list at
the bottom of the File menu. You can clear the menu entirely by going to
Tools | Options | General and setting the number for "Recently used file
list" to zero; OK to close, then reopen the dialog and reset to the desired
number. You can also remove individual entries by pressing Ctrl+Alt+Hyphen
and clicking on any entry (use this shortcut carefully, as it will remove
*any* menu item).
If your problem is that your Documents/My Documents folder is cluttered,
then create a subfolder for Correspondence and move your letters into it.
Then create a new subfolder for your story and add a shortcut to it to the
Places Bar in the Open/Save dialog.
Unless your hard drive is unusually small, there is no reason to actually
delete any document files. You should still have more than enough room for a
very long story, and deleting even hundreds of letters will make very little
difference. What you can do, however, if you have "Always create backup
copy" enabled, is periodically clear out the backup ("Backup of
<filename>.wbk") files, though, as you'll see, this is more helpful to
unclutter the Open/Save window than to actually make more room on the HD.
--
Suzanne S. Barnhill
Microsoft MVP (Word)
Words into Type
Fairhope, Alabama USA
http://word.mvps.org