Guys i figured it out, i too have a vista os. What you do is get the pfsetup.exe you downloaded, copy the file to your "program files folder" where the rest of your program files are stored. Do not copy it anywhere and do not run it from any other place on your computer other than in this folder. then install the program, you will no longer get that message. works 100%.
i remember that i tried installing a program in the past and it also didn't work until i did the above instructions.
Thank you would be nice!