Windows 7 Trouble Installing Flash Player 11 After Windows 7 Upgrade

I just upgraded from Vista Home Premium to Windows 7 Home premium yesterday, everything was fine, exceptional ya might say. And now, today, I cannot play any of the games at Facebook, or at MSN. They want me to install Flashplayer11. I try to, and it only gets 50 percent loaded and I get a message to shut down Internet Explorer, and I have nothing open. I have tried in safe mode, shutting off my antivirus, etc.....I do not understand what could have changed over night.....Thought I would add that at the Adobe site, it does not recognize a flashplayer version installed at all , yet at my programs, it shows Flashplayer11 is installed