Probably because of legal issues, or lazyness/arrogance.
However, if you want to play on the OFFICIAL SERVERS (Which are still very much online) you will need the westwood online installer.
Download it here:
http://zoaedk.noxforum.net/files/WestwoodOnline.exe

And for more information on how to connect, see this:
http://www.noxforum.net/index.php?topic=7566.0

The GoG release doesn't support Westwood Online because the official servers are not online, it has nothing to do with laziness or arrogance. Your links are for a private-server setup run by fans of the game.

No version of the game you can install, even if you were to use original discs, will cause Westwood Online to work because it doesn't exist anymore.

Oh really? Try going to http://servserv.westwood.com/ and see where you end up!
Westwood made the official server redirect to XWIS and had them take over support after they died.

The only reason this exe is hosted on zoaedk.noxforum.net is because the installer is a custom made one by the Admin of there. The original CD's install Westwood Online with them, but they never made a seperate installer.

I wonder why I can't play online on one of my computers, but on the other one I can?

It says I use the wrong password?!

And with the pc where it worked, I didn't have to register to Westwood Online.

But on the other one I have to?!

Solved:

Okay so the problem seems to be, I cannot log in with the same account on 2 differrent pcs

That's right, wuTz. Also, Maurice Ravel here, you joined my server. I hope to see you more often!

Now that I see this post I am VERY interested in playing this game online. I will try tonight to change the settings, make a Westwood Online account and log in. Is anyone thinking of hosting a game tonight or sometime in the week? If not I can host it myself. I really want to see what all the fuss was about regarding this game multiplayer component.

I just wanted to mention that I managed to log in just now to the game. Obviously the server was empty but it is very much online. I'm quite surprised GOG has not done anything to actually get this game to work for the actual servers, especially since it is so easy just to make an account name and log in. Such a waste of active servers and the possibility of people to continue playing this great game.

anyone still playing? ill play

Ban superjack46 I caught a virus after clicking on his links.

Ignore amansui, he probably has norton and doesn't know what a false positive is.