I have done what you suggested, but I think that I've found the issue; I forgot to mention that I have my laptop displaying on my Samsung TV through a HDMI lead. I tried loading Arma 3 without it plugged into my TV and it loaded fine. I've then tried to load Arma 3 with my laptop plugged into my TV and I get the same problem as before. However, I can load Arma 3 without being plugged into my TV, then once it has loaded I can plug in the HDMI lead and it plays fine. I'm not sure why this happens, as the screen is just being duplicated, but so far this is the cause of my issue.

Thanks for your help.