Believe me this problem drove me crazy, I had microsoft engineers link up 3 times with my laptop to try and fix it. Help is here, switch off the fast start up - ok my pc went from about 15 seconds to start to around a minute but this I can live with. HOW
- the easiest way for me because my pc know how is limited - tap the power button like when you go to close/switch off your pc - in there with all the other things like hibernate etc is blue power button settings, - tap this it opens system settings, in blue writing it says, Change Settings That Are Currently Unavailable click this - at the bottom tick the box to turn off fast start up and press save changes. This worked for me hope it works for you too.