Another method will be the Open Office which is a free selection of office programs, very much like msoffice, that includes a Word processor like Word. Open Office allows you to produce PDF also to read Word files. Here the feature set seems not really dissimilar, a little different from Acrobat and Expression , thus there could be difficulties with compatibility. However it is a well-supported open source software having an assisting and energetic user community. Appropriately, Adobe is definitely the best choice whether convert PDF back or you need to convert your Concept document. http://www.sofotex.com/Free-PDF-to-Doc-Converter-download_L134792.html