I'm using htmldoc to produce simple documents and trml2pdf (Python based) for quality printing.
I don't know if they run on Windows.
I recently tested the OpenOffice filters (with Java and JODConverter). They provide conversion from any odt, doc, txt, rtf and html to pdf, odt, doc, txt, rtf and html.
Unfortunately the rendering of the documents converted from html is awful, while the other conversions are quite good.