Is your laptop overheating?  One thing people rarely take into consideration is where they have them sitting.  In the majority of laptops, the fan to keep it cool is on the bottom. Keeping this in mind, placing your laptop on anything that blocks these vents will prevent the laptop from cooling down.  Laptops that over heat can have a bunch of different errors, so if you are having weird errors on your laptop, including but not limited to random shutdowns or restarts, feel how hot it is.  The same can apply to Desktop PCs if stuffed into a cupboard or next to something that blocks airflow.  In short, always make sure your laptop or desktop vents are not blocked, allowing cool air in and hot air out. Also, if you are out and about in the hot summer sun, limit the amount of direct sunlight exposure your laptop gets, as the fans are unlikely able to cool off that much extra heat.