It is also very easy to convert footnotes to endnotes, or vice versa (or both at the same time).
Instructions for downloading new styles are included in the link: There's one extra step if you're inserting a reference into a footnote. (Wherever your cursor is in your document -- the body or the footnote -- is where the citation will appear in the document.) There may be occasions where you want to copy all of the references used in a Microsoft Word document to an End Note library.
Roger wonders what could be causing this problem with the footnotes.
The answer could be quite simple, and related to using the Track Changes feature of Word.
Word doesn't renumber the footnotes because the footnote is still there—albeit marked for deletion.
When the changes are accepted or rejected, then Word will renumber the footnotes accordingly.
If you try to put your bibliography or appendix into “endnote space,” you are likely to run into trouble.