It is hard to know where to start without an understanding of the content of
your workbook.

To work around your problem (short term), click Tools, Options, Calculation
and change to manual. After you update data press [F9] to update workbook
calculations. It will still be slow to calculate but you will be able to
update or add data without going totally insane:-) After you figure it all
out, change calculations back to automatic.

If it is your workbook and not some other problem, the following may help.

http://www.mvps.org/dmcritchie/excel/slowresp.htm

If you are running VBA code:
http://blogs.msdn.com/excel/archive/...practices.aspx

Excel 2007?
http://msdn.microsoft.com/en-us/library/aa730921.aspx

You MAY find something he
http://social.msdn.microsoft.com/Sea...rformance&ac=3

--
Steve

"JMM" wrote in message
...
Am working on a spreadsheet that is not complicated. Entering data was
occuring normally, then it started to slow way down. I am putting in new
numbers over the pre-existing ones, and now I get the spinning circle
symbol
for about four minutes after each entry before I can make another entry.
If I
click in another cell, the screen gets a white overlay. What am I doing
wrong?
Thanks
John