I've just updated my ubuntu 15 to ubuntu 16. Now, every time I shutdown, the computer reboots after a few seconds! I've already googled for solutions but nothing worked. My computer is a HP probook 4540s.
EDIT: One more piece of information: when I restart instead of shutting down, I can no longer access the internet (via wi-fi). Also, I can get my computer to shutdown without rebooting if a press ( a long time) the (hardware) power button.