Tested in Windows 10, with NASM v2.14.02.
; ----------------------------------------------------------------------------------------
; INFORMATION
; MrNetTek
; Assembly Message Box
; eddiejackson.net/blog
; 3/9/2020
; free for public use
; free to claim as your own
;
; DOWNLOAD
; https://www.nasm.us/pub/nasm/releasebuilds/2.14.02/win64/
;
; SAVE AS
; hello_gui.asm
;
; COMPILE
; nasm -fwin64 hello_gui.asm && gcc -o hello_gui.exe hello_gui.obj && hello_gui
; ----------------------------------------------------------------------------------------
GLOBAL WinMain
EXTERN MessageBoxA
EXTERN ExitProcess
SECTION .DATA
MSG: DB "Hello, World!", 0
SECTION .TEXT
WinMain:
PUSH RBP
MOV RBP, RSP
SUB RSP, 0X20
XOR RCX, RCX
LEA RDX, [MSG]
MOV R8, RDX
MOV R9, RCX
CALL MessageBoxA
XOR RAX, RAX
CALL ExitProcess