What is the problem I'm having creating pdf files?

I'm trying to create a pdf by selecting "print" then Adobe Acrobat as the printer. Normally it will ask to save the document and then its created it as a pdf. Now, it creates the document as a notepad file.

Also, if I try to create a pdf from Adobe, select a new file and then click "open", I get the error message: "Missing Pdf maker files. Do you want to run the installer in repair mode." Have selected "yes", have also run the repair mode from the install disc as well as uninstalling and reinstalling the program. None of these things work.