can no longer insert new columns & unhide hidden columns

[em2]

I can no longer insert new columns in between previously formed columns, and
can't unhide the hidden columns. Using excel help did not help. Any
suggestions?

 

[Dave Thomas]

To unhide all the hidden columns, select the entire spreadsheet by clicking
on the square just above the row 1 and to the right of column A, or by
pressing CTRL+a in Excel 2007 or CTRL+a (twice sometimes) in Excel 2003. In
excel 2003 then select the Format menu, then column, then unhide. In Excel
2007, Home Tab, Cells section, Format, Hide & Unhide, Unhide Columns.

Do you get a message when you try to insert columns?