Thanks to all those that have helped by none of you were correct :P
After finding out that it showed in the Bios and sometimes
in My Computer, I started to wonder if there was a loose cable/ dust in the system.
I took my computer apart and there wasn't much dust (cleaned out every other month). I progressed to find the 'Sata' cable. I took it out (expecting a broken wire or something) and I was surprised to see that I installed a DMI cable instead (Desktop Management Interface).
Its clear that some
information was getting transferred between the hardware and PC but not all of it. I now have bought a REAL SATA cable and works a treat now.
The DMI cable on the left. At a glance it looks exactly the same as a Sata cable
The DMI cable is on the left. You can see that the pin structure is completely different from the SATA cable. Although there is the same amount of pins, I will assume that they weren't quite the right size to carry the information on the spacing was slightly different to the SATA one.
Lesson to be learnt.. Carefully check your cables if installing new hardware.