FREE! Convert to PDF from any application by simply 'printing' to the PrimoPDF® printer - it couldn't be easier! Within minutes, you can create high-quality PDFs by converting from Word, Excel, and virtually any other printable file type.
Completely FREE PDF Converter - not just a trial version.
Print to PDF from virtually any Windows® application.
Create PDF output optmized for print, screen, ebook, or prepress.
No annoying pop-up ads, no registration requirement - no catch!
High-quality, easy to use PDF creator for all users.
Ability to merge PDF files upon conversion.
Supports Windows Vista.
Converting A Word Doc To PDF
- Open the document in Word (this actually applies to virtually any program).
- Select File, Print. Select the PrimoPDF driver from the list of printers and click OK.

- The PrimoPDF options window will appear after the job has been spooled. You can use the Document Properties button to embed Author, Title and Subject information into the file, and you can specify Security options like requiring passwords to open the file and denying readers the ability to copy text or print the file.

- Also in the options screen, you can specify where you want the PDF to be saved to and you can optimize your PDF for screen, print, e-book or prepress.

- Set your options as required and click OK. Your file will be created in the location you specified and by default should open up in Acrobat Reader.
The great thing about this is that you can print anything to PDF - even web pages. I tested it with this site, and got a perfectly servicable PDF. Be aware though that unless there is a specific print stylesheet for the webpage, the styles are likely to be stripped out of the document. Nothing wrong with that as long as it’s readable.
Developer: http://www.primopdf.com/