For typing beautiful mathematic documents such as articles, books, reports, thesis and similar works you may need MiKTeX and WinEdt.

MiKTeX (pronounced mick-tech) is an up-to-date implementation of TeX and related programs for Windows (all current variants) on x86 systems. TeX is a typesetting system invented by Donald E. Knuth, who says that it is "intended for the creation of beautiful books - and especially for books that contain a lot of mathematics".
MiKTeX offers a complete set of utilities, macro packages and fonts.
Download and Install MiKTeX from here.

WinEdt™ (shareware) is a powerful and versatile ASCII editor and shell for MS Windows with a strong predisposition towards the creation of [La]TeX documents.

WinEdt is widely used as a front-end for compilers and typesetting systems, such as TeX or HTML. WinEdt's highlighting schemes can be customized for different modes and its spell checking functionality supports multi-lingual setups, with dictionaries (word-lists) for many languages available for downloading from WinEdt's Community Site.

If you want WinEdt to perform an editing task that is not already implemented in its default settings please visit an ever growing collection of macros, dictionaries (word lists), configurations (and more) at the "official" WinEdt Community Site.   

Download and Install WinEdt from here. Also you may need GSview and Gostscript.