If you have acrobat (and not just the reader) you may have a pdf toolbar in your wordprocessing programme (is it MS Word?) - have a look under view, toolbars. On this toolbar you should have pdf maker. click it and you will convert your document.
When Acrobat is installed it also installs itself as another Printer (Acrobat Distiller).......... Your document is then saved as a .pdf file by the print routine which choosing Distiller as the printer.