Yeah i've trying to get it full screen and i''ve looked at other similar thread about this

i've tried overlay, but its still a medium sized widow when playing.

From what I gather you play in windowed mode, check the fullscreen checkbox (if you have one).
Another method is opening the Dosbox%.conf file with notepad and edit the fullscreen=true line.

Fullscreen is already checked

also where is the Dosbox config in No Regret?.

In the folder where you installed the game.

Going by what i'm seeing 'fullscreen=true' its exactly that, But yet its not fullscreen like No Remorse

Try editing the line fullresolution=desktop.

I'm looking at the full resolution line and it has

fullresolution -- What resolution to use for fullscreen: original or fixed size (e.g. 1024x768)

different to other Dosbox config's that i've seen To what exactly?

Exactly that, desktop as in d e s k t o p. :)
Also make sure output is anything but surface, I recommend to choose overlay or ddraw.

Already setup as Desktop

and as for Output it had "output -- What to use for output: overlay,opengl,openglnb,ddraw" surface was in there but i deleted it

"edit"

not much has changed.

What do you have for output now?

Everything but "surface".