Are you using Origin to play Battlefield, Fifa? because if you go to Origin's support website I am sure you will find your fix there as for the AC1 problem I am unsure you have not really given us any indication of truly seeking assistance because you have not given us any information regarding your hardware, what the actual problem is.
Do the launchers start and then nothing happens, what exactly is happening? If you click the exe does it show the icon on the taskbar and then close or what?
I have used Win 8 for nearly a year now and I am one of the few people who actually like it.
I also game on it every single day (at least the days I am home) so I can with certainty say it is not the OS. Have you installed the proper drivers...