New laptops have lots to do: Indexing, download & install updates, And things like that. I would set it to never sleep and set the power plan to high performance (leave it plugged in, ok to turn off the display) and then check it in half a day and see if it needs to reboot. If its still doing this after a day of having the system to itself then I would call Lenovo since if its a hardware problem you'd have to go thru all their troubleshooting steps anyways. If you get no good results, return it and get something else.