From Aide CAD Systems:
This powerful program converts PDF to DXF (PDF to DWG) for editing in CAD. It converts thousands of PDF files to DXF files in one easy step, converts all pages in each PDF file, extract embedded images, and high quality, high performance, and simple to use.
I'm not sure why it didn't work. I downloaded this same trial years ago in XP and converted a rather large file that required a lot of clean up, but saved me HOURS or redraw. It was my intention to buy a copy because I have six or seven large files I now need to to do and it no longer works. Hugely disappointed.