You bound this to windows by using things WriteFile, did you made a copy/paste error because you don't import (extern) the Windows API functions (WriteFile, GetStdHandle or ExitProcess). If you write OS specific code obviously it will only work on that OS. Assembly can be used to create a 'hello world' for any CPU, regardless of OS. You could write perl code which will only work on certain OS. Assembly can run on a bare CPU, stated many times in the thread, stop talking round this. You make it sound like your way is the only way, and the right way, buddy it's not. These are bad habits, arguing against yourself, contradicting yourself, detailing threads, confusing OP by changing the terminology in different posts.