Because the Mac has a smaller market share and sometimes it's not worthwhile to make a port of a game for the Mac. Also, historically Apple was never interested in the gaming market (they focused on education) and there were much less Mac ports in the past than they are now.

Do you get any exact error message while loading the game? If yes, please let me know the exact error code. What is make and model of your computer? Which games are you not able to play on your system?

Were you able to play the games on your system in past? If so, when did the problem start and have you made any hardware or software changes recently? Are you talking about the online games or the games which are installed in your system? If the problems are with online games, update your flash player. Click on the link given below to update it: If you are not able to play games installed in your system, try the following methods and let me know if that helps you: Method 1: Try following the KB article to perform Clean Boot: How to troubleshoot a problem by performing a clean boot in Windows Vista and Windows 7 Disclaimer: After you used the clean boot to resolve your problem follow Step 7 to reset the computer to start as usual. Method 2: Check if you face the similar issue in safe mode.

To start your computer in safe mode go through the below mentioned article.