Try using a programme called primopdf. It's free and enables you to convert virtually any do***ent into PDF format. Even JPG. Very useful when wanting to send large pictures as the PDF is much smaller.
You have to download a PDF reader - I use Foxit Reader - then to save to a PDF do***ent you click on "Print", not "Save". Where is shows your normal printer by "Properties", click on the down arrow and you will see one of the printers is called "Foxit Reader PDF Printer" - click on that, then you will shortly see your PDF do***ent which you will have to save somewhere of your choice.
If you already have some other PDF reader, try the same method, some of them are very similar.