By default, Microsoft Office 2007 uses a new file format with the extension “.docx”. If you are trying to share files with users of older versions of Office, this can be a problem. Depending on whether you are the creator or the receiver, there are two ways to solve this problem. To create a more compatible file, users of MS Office 2007 can “Save As” in Office 2003 format. On the receiving side, users of older Office versions can grab a free upgrade from Microsoft that will allow them to read the new format.