I have used Advanced SystemCare for over a year and computer won't scan when I click the Scan button. I have uninstalled and reinstalled; I even purchased Pro edition. Everything downloaded fine, but Advanced SystemCare won't scan when prompted.
The Advanced SystemCare requires elevated access to work properly since it will need to scan system areas. Try running the software as Administrator and disable all the antivirus applications you might have installed on your computer. This could prevent you from running the application even if you uninstall or re-install.