How to: Change the default font for an active workbook.
Solution:
Select 'Style...' from the 'Format' menu. Select the style used in the workbook from the 'Style Name' drop-down list. Click 'Modify...' and then the 'Font' tab. Select a different font for the active workbook.
1) Select the 'Format' menu and select 'Style...'. (The Style dialog box appears.)
2) Select the name of the style used in the workbook from the 'Style Name' drop-down list.
Selecting a style
NOTE: If multiple styles are used, select the style for which the font needs to be changed.
3) Click 'Modify...'. (The Format Cells dialog box appears.)
the Modify... button
4) Click the 'Font' tab.
5) Select the desired font from the 'Font' list box.
Selecting a font
6) Select the desired style from the 'Font Style' list box.
7) Select the desired size from the 'Size' list box.
8) Click 'OK'. (The Style dialog box reappears.)
9) Click 'OK'.