I don’t have access to Word 2007 but if this is something you want to do going forward you may be better off creating a custom template for future documents. You could try select all the text and click the icon that increases the font ( I think that existed in 2007). This will bump it up to it’s next available size and keep the existing formatting. If this does not help come back with information on what font are you using and the current size. A change from 10px to 10.5px may not even be that noticeable, is the smaller font causing problems?.