Okay. Final update methinks. Remember this is all in full screen.
I uninstalled the touchpad software on the laptop just in case - same result.
On the main screen there are a lot of buttons at the bottom. I noticed that they will highlight as I move the mouse which makes me think that the mouse itself is moving around the screen as you wo9uld expect, however there is no visible mouse pointer. I changed the mouse pointer in the Control Panel (worth a try) but still the same.
So it looks like the mouse works, it's there and will move, highlight and allow you to click on things. However the pointer itself is simply not visible.
I have also ran the updater and updated to 7.009 but still same issue.
I'm happy to run whatever you need to to figure out what is going wrong. I don't believe it's the OS when everything else works. You guys don't believe it's the game as nobody else has had this issue so I'm not sure what else to suggest.
It works fine in windowed mode so it's a combination of this laptop and the game.
I appreciate the help Keith and Kahuna (although I'm still not sure if you were joking with your reinstall the OS comment!). Hopefully I can get on and play now!