I use Bitcoin Core 0.18 and Armory 0.96.5 on Windows 10 and it all seems to work fairly well.
I simply start the Bitcoin Core GUI (it's configured with a datadir of E:\Bitcoin)... and after it is up and running and synced, I start Armory (I've left it to just use the default Armory locations for it's databases etc, but that is easy enough to change). So, my settings in Armory look like this:

You will also need a "bitcoin.conf" file in your Bitcoin "datadir" that has the following line in it:
server=1
That will enable the RPC component in Bitcoin Core and allow Armory to communicate with your Bitcoin Core instance correctly... In the Bitcoin Core GUI "network" settings (Settings -> Options -> Network), you need to check the "Allowing Incoming Connections" option:
