There are several troubleshooting steps available on this site. If none of these work, it's possible that your screen is defective. Please refer to the following link: ASUS D550MA-DS01 Troubleshooting
High end video games require a lot of computing power and memory to handle the math functions required to generate the graphics and physics. This specific laptop comes with Intel Integrated UMA, which means that the graphics are powered through the onboard chip. In most cases, this means that there is not enough power to run high end games. The chip is only designed for simple things, such as surfing the web or watching a movie. You'll also be able to play most web-based games that are not resource-intensive. This is not the laptop to roam through a forest hunting dinosaurs or hijack cars to complete mission objectives. If you're looking for a laptop that has the capabilities to play current games, you will need to find a laptop that has an external GPU with the specifications necessary to handle your favorite video game.
The laptop can be upgraded to a larger or faster hard drive based on the 2.5" SATA form. There are upgrades available for 6.0 GB/s SATA hard disk and solid-state drives with sizes greater than 1 TB.