File+downloads+as+a+zip+file

When you try downloading one of the Office 2007 file types such as .DOCX, .PPTX, .XLSX, the file may download as a .Zip (Compressed Folder). This happens if the Office 2007 file format MIME types are not registered in the Web server you’re downloading the file from. There is nothing much the user can do, apart from saving / renaming the file with the correct extension and then opening it using Office 2007. If you had already downloaded the file (as .zip), simply rename (change) the extension accordingly. To do that, you’ll have to clear the Hide extensions for known file types check box in Folder Options. (**REF** Show or hide file name extensions)