Why won't movies play after reinstalling Windows 7 with IE9?

After reloading Windows 7 because of a nasty virus, I cannot get movies or games to display properly. I have deleted Real player, uninstalled and installed Flash Player 5 times and followed all of the procedures listed to solve this problem. Nothing has made any difference. Movies flash and remain black unless you can find the maximize icon and then, in full screen mode it seems to work fine. Games on Facebook flash off and on momentarily. Even adds on web pages won't display correctly.  Something is incompatible but what?