There are several reasons why one should prefer LaTeX to a WYSIWYG word processor like Microsoft Word: portability, lightness, security are just a few of them (not to mention that LaTeX is free). There is still a further reason that definitely convinced me to abandon MS Word when I wrote my dissertation: you will never be able to produce professionally typeset and well-structured documents using most WYSIWYG word processors. LaTeX is a free typesetting system that allows you to focus on content without bothering about the layout: the software takes care of the actual typesetting, structuring and page formatting, producing documents of astonishing elegance.