First I started to research about docx. then I find out that its a openxml based open standard of new microsoft office 2007 file standard. it sound complex and its a complex issue anyway. because there is no viewer for it other then MS office.
then I look for a converter for it. in is sourceforge I found a project named as odf-converter here is the link. ODF has good projects. and promising but in alpha stage Office Open XML C# Library this one will be good.
why am I talking about ODF(Open Document File) because actually docx and odf is really similar. they both zipped xml files structure. openoffice and microsoft office will use open file standards.
odf-converter can convert docx file to odf that is the function of docxviewer because it shows odf actually. converted from docx. everything written in c# under .net2 framework.
main purpose of this project is to open docx with a small viewer. I could not make it work without openoffice but it will work if you have openoffice installed your machine.
7-zip or any other 7z opener.
open docxviewer.exe then file->open from menus.
choose the .docx file then open. it will convert docx to odf and open it with webbrowser component of .net2 if you dont have open office installed it will just show blank page of internet explorer. then it will open docx file in odt format because its been converted.