It looks like CLICK HERE from John lewis. I purchased one for my Mother and took it back as it seemed slower than the computer it was replacing (this may have been just me as I was comparing it to the one it was replacing).
If it is the same as the John lewis one, inside the case you will find a small mother board smaller than a Matx with no expansion slots not even to add a graphics card, CPU + fan + one case fan and memory nothing else you can not even add an extra HD. The power supply is like the power block you get with a laptop and connect to the outside of the case. It has no USB3 or SATA3 connections. The Argos one has win 8 installed but can be upgraded to 8.1 via the App store. The John lewis one has now, by the looks of the web page been updated to win 8.1.
Its a basic computer for basic needs.