It's just started happening in Facebook games like Cityville. It plays ok for awhile and then I get the lines across the screen. It's happened twice this morning. Is this a graphics card issue? It's like all the graphics are smashed up together for a minute.
It has the ability to modify various system settings as well. But resist the temptation until you fully understand what is going on. Only problem with Speedfan often cannot tell you which sensor is which if there are multiple sensors.