If you have such a major issue with standard dialog display - not showing the directory tree is certainly a major issue - I would also suspect a virus. I not sure what "removed anyting" means. It may require removing and reinstalling the operating system. A pain to be sure, but it sounds like what is needed.

It COULD be one of the many screwed up add-ins that mess up Word. Can you get normal save dialog with other office apps? If they are normal, then it is quite likely an add-in problem.