Introducing Elementary OS. It is a Ubuntu Linux variant. It is very, very, easy to use, one might even say "elementary"? :) Honestly, if one can use a smartphone or tablet, one can use this operating system. The install was super easy. It detected all of the hardware on this HP DC7700, onboard network, sound, and video. I later added in an Nvidia 1gb PCI-e video card and a cheap USB wireless network card, it added all the drivers automatically with almost no intervention from me. It did dual monitors without any hassle. It is also quite fast, great for breathing new life into older hardware.
The built in web browser is quite sufficient, YouTube and what not works just fine. Amazon Video streaming does not work. Installing Google Chrome is a bit of a chore for those not familiar with Linux. The App store has plenty of software available. Getting Java installed correctly is a challenge I am still working through.
In summary, I am impressed. If you got a machine laying around it give it a try. If you got people in your life that are "not good at 'puter" this might be an answer.