Have tried three times to install Adobe Reader on my Mac. Operating System OS-X 10.5 (Leapord). I designate that I want to install on the harddrive but during the installation process it requests a disc and freezes the computer so that I have to Force Quit. At one point I thought I might fool it by inserting blank disc but, of course, would not accept it. Don't understand why it would want a disc of some sort when I designate the HD as target for installation.