RoonServer on Win7 64 - Can't detect server under "Configure Roon OS Devices" [Answered]

ServerBox is a little passive media PC - Core i5 120GB SSD 1TB Storage Win7 64 Bit.
Client is a W10 64 Bit Lapdog - Core i7 500GB SSD.
Everything under roon works. The server is up and serving just fine.Wired GB network. Fire up the W10 client and it plays merrily to my AMP over HDMI via the Core. Ports have been opened for UDP & TCP, firewall rules appear fine.
The only thing it doesn’t do is allow you to configure the server from the client PC.
On my work setup (Win7 Client and ROCK installed with the standalone linux svr OS) I can browse to the IP address from a browser (same as hitting the “Configure Roon OS Devices” button under Settings > Setup.
On this setup I can’t.
I’m guessing that it’s because the Win7PC has the IP address, where as running the Rock at work it’s the server serving the IP address.
Will it just not work in my above config, or am I missing something plain & obvious ?

Is only for Roon OS Devices. RoonServer running under Windows is not a Roon OS Device.

Ah, thought as much.