Pfthb

I think DEBUG.EXE still ships with windows (at least it does with XP). Run debug and enter something along the lines of the following transcript:

c:src> debug
-a 100
1373:0100 mov ah,9
1373:0102 mov dx,108
1373:0105 int 21
1373:0107 ret
1373:0108 db "Hello world!$"
1373:0115
-n c:hi.com
-r bx
BX 0000
:0
-r cx
CX 0000
:15
-w
Writing 00015 bytes
-q

c:src> c:hi.com
Hello world!

c:src> _

Read more on DEBUG.EXE at: http://en.wikipedia.org/wiki/Debug_(command)

And the INT 21 display string http at: http://www.uv.tietgen.dk/staff/mlha/PC/Prog/asm/int/21/09.htm

Follow these steps:

1. Get and install Turbo C 2.0 from here, legally.


2. Copy this code (*)


3. Compile it.


4. Your hello.exe is ready to run.

This is code you should copy (*):

int main(int argc, char **argv)

 printf("Hello, world.n");
 return 0;

DJGPP is a complete 32-bit C/C++
development system for Intel 80386
(and higher) PCs running DOS. It
includes ports of many GNU development
utilities. The development tools
require a 80386 or newer computer to
run, as do the programs they produce.
In most cases, the programs it
produces can be sold commercially
without license or royalties.

http://www.delorie.com/djgpp/

For C and C++ development, use one of these free and open source compilers:

• 
  DJGPP - a DOS port of GCC. It builds 32-bit protected mode DOS applications.


• 
  Open Watcom - I'm not as familiar with this one, but it's actively developed and can target 16- and 32-bit DOS, Windows, and OS/2.

This will do it straight in the command line debugger in DOS.
http://www2.latech.edu/~acm/helloworld/dosdebug.html

It does write a COM file and not an EXE (there is a difference) but should be a good start for you.

You want a MS-DOS C compiler. Is there still an old version of Borland C floating around? Also, you might find a port of the GNU C compiler for DOS.

Install Turbo C/C++ 16-bit compiler. Then create new noname00.c file.

Write this code in it.

//Include necessary files stdio.h and conio.h for function prototypes.
//The "int agrc , char *argv" are optional parameters to main program.If you don't want to use //it you can just write "int main()"
int main(int argc,char *argv) 
 
 printf("Hello World !!!!"); 
 getch(); 
 return 0; 

the .exe file generated by this compiler can be found in source directory.

Try to run it in your own MS-DOS Box.

It should run.