To upgrade from a previous version of PDF to DOC, click START-> CONTROL PANEL. Find Add/Remove Programs. Remove ALL CTdeveloping products (PDF to DOC, PDFtypewriter, PDFconverter, etc). Then download the DEMO as described in 1.01 Downloading PDF to DOC

Once you have installed the new demo version from the website, your pre-existing registration should be recognized and the full version will continue to be installed on your system.