Can you post the contents of the FlashInstall.log file from syswow64\Macromed\Flash?
After that try the offline installer http://download.macromedia.com/pub/flashplayer/current/support/install_flash_player.exe
Can you post the contents of the FlashInstall.log file from syswow64\Macromed\Flash?
After that try the offline installer http://download.macromedia.com/pub/flashplayer/current/support/install_flash_player.exe