The problem 

My HP Ultrabook running Win 10 can connect to the WXC modem/router but finds no Internet connection. 

Other devices can connect to the  Internet via the same connection -  e.g. iPad, phone, other laptops. 

The Ultrabook can connect wirelessly to my phone which is running as a hotspot  (ironically  it's connected via the WXC modem). 

All of this has been working flawlessly for years. Last week we upgraded the WXC connection from VDSL to Fibre - still no issue with any device connecting. 

The only thing that changed was last night I connected an older laptop to the network for the first time for about a year. It had previously been connected on the same network as my Ultrabook. It had some trouble finding the Internet -  Windows 10 fixed the problem automatically (to my shock - never had that acutally workybefore) It's still connected just fine. 

Late last night I was connected fine on my Ultrabook - but this morning it wouldn't connect using wireless at all. (I haven't got a spare length of ethernet to try wired) I did some research - again Windows 10 decided there was a problem with device_power_state_failure  after a reboot I got to the current state. 

The message  Iget is "connected, no internet, secured "