Sumatra PDF is a Free and Open Source Software viewer of Adobe Acrobat® files (also known as Portable Document Format (PDF) files), eBook (ePub, Mobi) and .XPS files (Open XML Paper Specification originally developed by Microsoft). It is a single executable file so it is portable (it can be run from removable flash drives without installing in Windows).
You can create PDFs from any Windows application wih PDFCreator