While I have never used that brand, I have attached a number of Windows 7 machines using powerline and I have only ever had to install the powerline driver on the machine attached via powerline. Most will then connect to the router where the other adapter has an Ethernet cable attached to a router LAN port.
I would remove any USB attached devices that you don't need to have attached while installing the drivers.
The problem comes in if your particular powerline adapters set up their own network, hopefully that will not happen as it requires a bit more work.
You probably need to run their software utility to complete the setup once you have both the adapters plugged in and attached with Ethernet cables to the router and computer respectiviely. I didn't expect the manual to be very clear when I saw the web site.