Both the keyboard and screen work. The screen is my TV, I have the computer hooked up via a HDMI cable to my TV. It did occur to me that it could be the screen or keyboard but I hooked the keyboard up to my laptop earlier and connected the laptop screen via the TV using the same HDMI cable and it works fine.
Guessing it must be Windows 8 as the PC turns on just fine and the brand logo appears on screen after start. The windows icon appears with the little round loading circle and then it switches to black screen at the point where the desktop should appear.