Many modern Windows applications have the ability to export a document as a pdf file. But where this is not possible you can use a freeware PDF software that acts as an alternative printer device to output files to PDF. They are applications that can build PDF files from any program which has a printing function.The one I use myself is PDFCreator which I have had no problems with to date. Some new reports I have seen indicate that this software is now bundled with Adware, which is unfortunate, but a sign of the times. I have an older version of this software, so I have had no experience of this situation.
Softpedia advises that "Users are advised to pay attention while installing PDFCreator for the following reasons:" and goes on to state that it offers to change your homepage, your default search engine and to download additional software components such as browser toolbars that are not required to use PDF Creator. That said, It seems you should still be able to still install it without the added software as long as you pay attention. It would also be prudent in this situation not to use any updates for it via the internet, or else such software might still get loaded without your permission.
An alternative would be to look for an older version of PDFCreator, or to use another virtual PDF printer device software. I would be happy to hear from people who are happy with another alternative freeware PDF print device software. So please list them here in the comments section.