Just a short time ago I was in a remote session in Windows 10 on my Inspiron 580, online and pursuing a particular subject when I suddenly lost connectivity. My monitor dropped back to my main desktop display. I tried to reconnect via Remote Desktop, and the machine couldn't be found. My modem/router was showing a connection, the LAN lights on the back of the 580 were lit, but it wasn't available.

I connected directly via mouse/keyboard/monitor and the modem icon in the notification area had an X overlay. All the Windows troubleshooting indicated that the gateway was unavailable. The modem/router was still showing a connection, and I had internet connectivity with my main desktop. Next I tried a restart, which took a couple of minutes of the marbles circling before it actually rebooted.

When Windows came back up, I got a message that it had dealt with a "Device Power State Failure", was collecting some information to forward, and then it finally booted Windows. Now the modem icon in the notification area had an X overlay. I did a right-click on it and opened the Network and Sharing Center, which displayed a generic NIC icon which was labeled "Disabled". I right-clicked it and selected "Enable", and the icon changed and added the ID of my NIC, then showed the name of my LAN and reported "Connected".

I launched Project Spartan/Edge and had internet connectivity. Next I unplugged my mouse/keyboard/monitor and reconnected using Remote Desktop, and everything is back to normal. "Device Power State Failure" is said to indicate a problem with a device driver, with suggestions to uninstall, etc. etc. I've made no changes to any drivers, and Device Manager still shows the same NIC ID and the same Microsoft driver from 2013.

A bit of a head-scratcher, but once again all is well.