If the text box won't resize in Word or Excel, check if the document is opened in the Compatibility Mode, and convert it to a newer format.

Editing text in Word 2007's text boxes is similar, but you'll need to actually click on the text box to activate it so you can "get inside." Unlike standard text on a Word document where you ...

Enter the new font size value in the Size section, such as "12" or select from the list. The Preview box near the bottom will display the selected sample text with the selected font size.