I installed Docker-Toolbox just now while following their webpage
I started with Docker QuickStart Terminal
and see following
I ran into this exact same problem yesterday and none of the "popular" answers (like fixing DNS to 8.8.8.8) worked for me. I eventually happened across this link, and that did the trick ... https://github.com/docker/for-win/issues/16
Between Docker for Windows, Windows 10 and Hyper-V, there seems to be a problem during the virtual network adapter creation process. Specifically, you might end up with two "vEthernet (DockerNAT)" network adapters. Check this with Get-NetAdapter "vEthernet (DockerNAT)"
(in an elevated PowerShell console). If the result shows more than one adapter, you can disable and rename it with:
$vmNetAdapter = Get-VMNetworkAdapter -ManagementOS -SwitchName DockerNAT
Get-NetAdapter "vEthernet (DockerNAT)" | ? { $_.DeviceID -ne $vmNetAdapter.DeviceID } | Disable-NetAdapter -Confirm:$False -PassThru | Rename-NetAdapter -NewName "OLD"
Then open up Device Manager and delete the disabled adapter (for some reason you can do this from here, but not from the Network and Sharing Center adapters view).