How can I send messages like "hello world", and receive from another computer using tcpip? Any code-example using VB6?

yeah do a google for "winsock client/server"

thank you, I found something according to your suggestions.

Yes winsock is the solution. You can also try to use MAPI control.

if you dont want client/server model, but want peer to peer then look into multithreading

you can also use an external utility to send messages through a network.
use the "net" utility.
from vb u can use it with the shell function

for example :-
where "server" is the name of the remote computer you are trying to send message and "heelo world" is the msg to be sent.

mind that this utility works in winxp platform only.

regards
Shouvik