It's actually two different windows or views into the same workbook.

Select the window you don't want and hit ctrl-w.

Then save the workbook--or you'll be doing it again.

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

DOUG wrote:

IMUST HAVE CREATED A NEW WINDOW OF A SPREADSHEET I WAS USING CALLED
TIME07.WHAT EVER I ENTER IN ONE IS ENTERED IN THE OTHER ONE.EXCELL LABELED
THEM TIME07:1 AND TIME07:2. hOW DO I GET RID OF TIME07:2 SO I JUST HAVE THE
ONE FILE?

--

Dave Peterson