Download the installer and save it to your disk http://fpdownload.macromedia.com/get/flashplayer/current/licensing/mac/install_flash_playe r_12_osx.dmg
then restart your system and run the downloaded installer before doing anything else.
Pat has the BEST advice for this.
However, if you run a social media plug-in called "MenuTab" it'll load at startup and will show a "false open" for Safari.
You'll need to "kill the process" using Activity Monitor in your Applications/Utilities folder.