I installed CS$ Design Premium on a Window 7 Ultimate 64-bit laptop running Microsoft Security Essentials. Flash CS4 will not install. Also, when I ran updater after the installation, Camera Raw 5.5 updater would not install nor would an update to Version Cue. I downloaded a Camera Raw updater to the machine and it updated Camera Raw 5.5 64-bit beautifully. Still no Flash however. I tried disabling Microsoft Security Essentials but I still could not get Flash CS4 to install.
Did you run the installation as administrator?