+1 to Norman as well.  I found this useful comment: http://www.busydevelopers.com/article/44081342/%26quot%3BThe+term+'Install-ContainerOSImage'+is+not+recognized+as+the+name+of+a+cmdlet%26quot%3B+on+build+Build+14385

And did this in PS:
1) Start-BitsTransfer https://aka.ms/tp5/6b/docker/nanoserver -Destination nanoserver.tar.gz

2)  wget -uri http://aka.ms/tp5/update-containerhost -Outfile c:\Update-ContainerHost.ps1

3)  C:\Update-ContainerHost.ps1

4)  C:\Update-ContainerHost.ps1  (again, b/c the first one failed with a file not found)

5)  docker load -i nanoserver.tar.gz

6) docker images

7) docker tag 3a nanoserver:latest

8) start cmd

9) in the command window> docker run -it --isolation=hyperv nanoserver cmd

Nothing happens, which is, at least, better than a BSOD