Office 2007 came with a new file format, “docx” which cannot be opened by anyone who does not have office or have older version of Microsoft Office. But now, there are ways to open .docx file even if you dont have Microsoft Office 2007.

Your first and the best option is to download OpenOffice. OpenOffice.org is the leading open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers.

I personally use openoffice and i think its really good and beast of all, it is free. You download it here.

There is another Option. If you use firefox, the install OpenXML Document viewer extension. It help you open Word 2007 files with all the formatting and layout preserved.

Another option is that you can use Docx Converter. Docx Converter which help you convert a Microsoft Office .docx file into a simple html file.

Last option is that you can install Microsoft Office Comaptibility Pack for Office 2007 and it helps you open Office 2007 documents in older version of Microsoft Office.

Hope that helps. So if you know any other thing which can help, kindly tell.