There are several third-party programs which may convert Word documents into portable document format aka PDF. But I don't know they are freeware or paid as I never used. I always convert my Word Documents into PDF manually. If you are using MS Word 2007 then you can try this:
- First open Word documents what you want to convert into PDF.
- Click on Office button.
- Click on Save as.
- A small window will pop-up. Scroll down the arrow shown in front of Save as type.
- Select PDF (*.pdf) from the list.
- Click on Save.
Your Word document will be converted from .docx to .pdf. But this can be done only in latest versions of MS Word, like MS Word 2007 and 2010. Hope this will helpful.