Do you see something like: Book1.xls:1 and Book1.xls:2 in the title bars?

If yes, then you haven't duplicated any worksheets. But you have opened a
second window into that same workbook.

If you want to close one, just click on it and hit ctrl-w

Remember to save the workbook before you close--else you'll be doing it again.

Debra Dalgleish has some instructions with pictures:
http://contextures.com/xlfaqApp.html#TwoWindows

This can be caused by using:
Window|New window
(maybe followed by window|arrange)

It can be quite useful to see different ares of the same workbook (even same
worksheet) at the same time.

math4mama wrote:

when i opened a workbook, excel duplicated it. i now have two workbooks that
open at the same time numbered #1 and #2. when i close one, they both close.
howdo i delete one?

--

Dave Peterson