I have a 1920x1080 windows 8.1 Laptop and I want to open cortex command fullscreen but no matter what I do I cant open it. I previously had the white screen glitch and I followed some online guides that other members posted to fix that but now I cant get the game to open fullscreen at all, it always bugs with a strange blackscreen then my laptop quits. I have intel hd 4400 graphics and I have updated to the latest driver. Please help !

Yeah I've had problems with the game's fullscreen too. There may be ways to actually solve it but if nothing else shows up you can always open up settings.ini in base.rte and change the res to something that works or set fullscreen to 0.

hmm Ill try that , do you know the best resolution that is closest to hd ?

No idea. What I did when I really wanted something hi res like 1920 x 1080 was windowed mode with the res and hide my taskbar haha.
I'd say just play around with it a bit and see what works for ya.