Problem:

When I open a PDF file created by Win2PDF, it shows up with random characters instead of the expected document format.

Solution:

Make sure the PDF is opening in a PDF viewer such as Adobe Reader, and not a program such as Microsoft Word which can't view PDF files.  If the Windows file associations for PDF files are incorrect, the PDF files may open in the wrong program.  To resolve the problem, you need to change the file associations so that PDF files open in Adobe Reader instead of a different program.