Installed Hyper-V Server 2012R2 on a server. Did NOT join the server to a windows domain.
Via sconfig.cmd I configured the network adapter, enable icmp, verified I could ping other PCs on the same lan segment and they could ping me, and enable remote desktop.
When attempting to remote desktop to the server I get this error:
As others noted this issue is caused by the fact that sconfig.cmd will only enable the firewall rules for the Domain profile. Because this server is on a workgroup you have to enable it yourself with Enable-NetFirewallRule or as the poster noted an equivalent netsh command:
netsh advfirewall firewall set rule group="remote desktop" new enable=Yes