Western
I tried that before and it did not work, as soon as I drop the mod into the DBW folder the game will not start, but just to be sure I have just tried it again.
Using an absolutely clean version of the game, NO mods added, game runs fine, drop SAS AI, Engines, Hotkeys & Carriers Mod v2.5 into the DBW folder and the game will not load.
So it has to be something to do with that mod and a conflict with the basic game files, I wonder what is different between your version and mine, I assume we downloaded them from the same places.
I'm using windows 7, is it something to do with that.