Sometimes you want to open a .docx file in a computer with only office 2003, you can always download the Microsoft compatibility pack from here
But if you are in a hurry, don’t have Internet or just want to check it out do the following:
Rename the file myfile.docx to myfile.zip (in fact a docx file is a zipped set of files)
extract the content
from the extract folder open word\document.xml
The file is really in xml format and it wont have the same structure as the original file, but you can always read the content and that’s the thing, right?
Notice that many applications will crash when trying to open the file (including wordpad, word 2003, Internet explorer) and thats a major bug in all microsoft apps, try notepad or opera to open the file.