I have the D-Link DXN-221 kit
It works great with my home network and is faster and more reliable than wireless, but only if you use logic and not the diagrams they show you.
First of all, when I first hooked it up trying to use their diagrams, it kept disconnecting the modem from the ISP and I could never get the setup to work. Perhaps I misunderstand or misinterpreted their diagrams, but perhaps they just were too vague. Getting through to their support team is difficult at best. It is not supported at the lower levels, you have to be routed to a Senior Product Manager who specializes in this device! I never did get any support.
Here is what I finally ended up doing and it works spectacularly and reliably.
1. If you have satellite, you need to buy a Tru Spec T-3 triplexer (or equivalent). It separates out satellite, FM, and CATV frequencies. Connect the triplexer to your wall. Connect the CATV port of your triplexer to your Coax IN port on the DXN 220. If you only have a cable TV and not satellite, just hook up the DXN 220 IN to the wall using a standard CATV cable (they supply two).
2. Connect the TV OUT (ignore the TV part, it is just an out from the diplexer contained within the DXN 220) to the input of a Channel Vision C-0314 1 In 4 Out Amplified Splitter (or equivalent).
3. Connect your Cable Modem Coax connection to one of the 4 output ports on the Channel Vision.
4. Connect an Ethernet cable from the DXN 220 to one of the LAN ports on your router.
5. Connect your WAN port on the router to your Cable Modem.
6. In the other room, connect the Coax IN to the Coax connection in the wall (you can insert a splitter first if you also watch TV in the room).
7. Connect an Ethernet cable from the DXN 220 to the computer.
If the Power, LAN, Coax and 100 Mbps LED lights are on, you have a connection and there is really no need to worry about installing the software and configuring anything; it just works. If the Coax LED in front of the DXN does not glow, you do not have a good Coax connection. The only things you configure are some passwords, the frequencey (or SCAN) and Pass All if you do not need to watch TV. The defaults were fine for me.
The Channel Vision not only amplifies the signal in order to prevent yourself from being disconnected from the ISP as I was, it also allows you some flexibility in how you add devices to your network. The Channel Vision also has an internal filter to eliminate noise.
Good luck with this. I would recommend this to my clients who have problems using wireless and I know that it would work just fine.
By the way, I am using Windows 7, Build 7100 on two built-to-spec computers, one built by me and one built by AVA-Direct. (AVA's build is neater and nicer than mine.)