How to: Change default font for all new workbooks.
Solution:
Select 'Options...' from the 'Tools' menu. Click the 'General' tab and select a different font from the 'Standard Font' drop-down list.
1) Select the 'Tools' menu and select 'Options...'. (The Options dialog box appears.)
2) Click the 'General' tab.
3) Select a different font from the 'Standard Font' drop-down list.
Selecting a different font
4) (Optional) Type the desired font size in the 'Size' box.
5) Click 'OK'. (A message appears indicating that Excel needs to be restarted to allow the change to take effect.)
6) Click 'OK' to dismiss the message.
7) Exit Microsoft Excel.
8) Restart for the change to take effect.