Our gaming pc's have been built specifically for Minecraft and Roblox. . You will need to press the ESC key when the game has launched and then go into the settings page.  Once in the settings page you need to change the graphics mode from automatic to the lowest setting using the left arrow key.  This will change other settings to match.  If the game runs fine you may want to go back into the settings and change to medium and run it again to see if stable or change settings back to low.  If you are looking to play other games on this PC, please check the minimum requirements before purchasing