Additional info on the "why" part.

ToolsOptionsCalculation can be Auto or Manual.

Excel takes the Calculation mode each session from the settings on the first
workbook opened in that session.

i.e. If you saved Book1 with calc mode in manual and opened it first, calc
mode would be in Manual.

If you saved Book2 with calc mode in auto and opened it after Book1, Book2
would be in manual mode(Excel ignores the auto calc mode in this case).

If you close Book1 before opening Book2, Book2 will be in auto calc mode.

Confusing enough? <g


Gord Dibben MS Excel MVP

On Thu, 5 Mar 2009 06:33:01 -0800, TetrahedreX
wrote:

Thank you, that worked perfectly.

"Mike H" wrote:

Try,

Tools|Options - calculation tab - select automatic

Mike

"TetrahedreX" wrote:

My version of Excel recently started acting strange. I have a complex
spreadsheet with many cells that depend on other cells for their content.
Today, for some reason, the cells do not update themselves. If I change a
cell, the cells that use formulas to get part of their content from the
changed cell do not update automatically. I have to manually go in, click on
the formula, and hit enter in order to get them to update. I've tried
searching for information on how to get the cells to update to no avail, and
restarting my computer did nothing. How do I fix this?

Note: This is in Excel 2007.