When I try to install Adobe Flash Player 11.3.300.257 after I click OK in the User Account Control dialog box , no installation happens, but I can see install_flashplayer 11x32_mssd_aih_d.exe in the processes in Windows Task Manager. I cannot install Adobe Flashplayer at all, and I have no Flashplayer installed. I use Firefox and Windows 7.
Download and run the offline installers from http://helpx.adobe.com/content/help/en/flash-player/kb/installation-pr oblems-flash-player-windows.html#main-pars_header
Make sure you kill the install_flashplayer 11x32_mssd_aih_d.exe process from Task Manager before running the offline installers.