The first thing I did was go to http://pdf995.com and downloaded the printer driver and free converter. Follow the directions to install it to your computer. I have used this program for several years with several computers and have never had any problems with it.
To create PDF files, simply select the "print" command from any application or program. Look for the printer selection - your current printer will most likely be chosen. Click to choose "PDF995" and click print.
You will now see a screen (below) that will show you two things: one is an ad from PDF995 - I just click out of it. The other will be a popup - I choose "continue using the sponsored version".
Tip: Every time I use my printer, I make sure that the correct printer is chosen. I can't tell you the number of times I have forgotten to choose PDF995 when making a PDF and end up printing out physical copies - and vice versa: creating PDF's when I meant to print copies.
Of course there are options to upgrade this program so you don't see the ad. If that ever became bothersome to me (and after years of using it I don't think it would), I would probably upgrade my desktop publishing program instead. Not only would I be able to convert my documents to PDF but it would also unlock other capabilities. I do have one other desktop program that converts to PDF but I have not had to learn the overall program so I've been sticking to what I already know.