Typical Office 2007 documents use 4 letter extensions. These include .xlsx for Excel, .pptx for Powerpoint and .docx for Word. Access however, uses .accdb as an extension, so it has 5 letters.
the Microsoft word files are called document
.doc
.DOCX
Create a new document in any of the office 2007 programs and save this document.
extension .docx
xlsx is the main extension used for Excel 2007.
.docx . They changed the extension from Word 2007. Meanwhile, you can choose to save the document in the old format (Word 1997-2003)
.docx, all Office 2007 have a "x" on the end.
It is a macro-enabled workbook from Office 2007.
doc for Word 2003 and docx for Word 2007
In Microsoft Office 2007 and 2010, the extension is .pptx, whereas in earlier versions it was .ppt.
You cannot change the format from Office 2003 to Office 2007, the technology was not out then. But you can make a RTF document that will open in Office 2007. Click on File/Save as/click on the arrow to open the drop down list/ choose RTF