A family of Microsoft word processing software products for creating web, email, and print documents.
Office 2007 is a version for the Windows operating system. If that's what you're using you've posted to the wrong Community. This one is for the Mac versions. When posting it's best to select the appropriate version information as well from the list of filters on the left. We'd help if we could, but issues of this nature are approached differently on the 2 platforms.
This link will take you to where you need to be... For future reference, note the settings on the left of that page. (I chose Windows other as the Office Sub-topic because you didn't specify your OS version.)