If the workbook is shared, you won't be able to merge cells.

To turn off sharing, choose ToolsShare Workbook, and remove the check
mark from 'Allow changes by more than one user at a time.'

pm wrote:
I was given a formated spreadsheet and needed to make changes. One change
was to merge a few cells. when I opened the format cells menu the merge
cells check box was greyed out. I can't find how to enable this function.


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Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html