A family of Microsoft word processing software products for creating web, email, and print documents.
You will need to have your document in Word 97-2003 (*.doc) format and then, when you select the Text Box, you will see the Text Box Tools>Format tab of the ribbon. If you then click on the dialog launcher in the Size section of the ribbon, you will see the Format Text Box dialog and on the Text Box tab of that dialog, there is a "Convert to Frame" button.