This time i done a lot of research. When i was using Windows 8, I Can play AC3 Smoothly. But after Updating to Windows 8.1, The game lags Often. what Can i Do? I suspect Windows 8.1 is causing all this
Why don't you try to do a clean install and try the game again. Also please make sure that you are running the game with Latest Game Patches and Updated Graphics Card Drivers. Make sure you are up-to-date Thanks
Also possible that the game isn't supported by Windows 8.1! Coul;d be also an Direct X Problems, means the latest version isn't supported by the Game! Firstly I would contact the Game Developer for to check out the support for Windows 8.1!