I wonder if Google will allow you to define file types one day. That would be helpful for those who have legacy files.
via What’s On My PC
Trying to open .xlsx, .docx, or .pptx file in Office for Mac 2004:. If you click on the link above you will learn that you have to download and install the Open XML File Format Converter. Nice that you have some forward compatibility. MS changes its download links or I would have included it in this article.