When I use Works spread sheet I can't change the font or text size in the header or footer. When I highlight the text and move to the toolbar I can't select anything. It works in the body of the document.

Works Spreadsheets do not technically have headers or footers. Chances are that the "Freeze Titles" option is enabled to create a header like effect. Try highlighting the cells you cannot edit, click the "Format" menu and uncheck "Freeze Titles."

Post back with your results.