Hi. I have my original Dreamweaver MX 2004 software on a CD/DVD with the serial number .

I think that ship has sailed my friend.  Macromedia went out of business in 2006.  And MX 2004 is 18 years old.  Those activation servers are long gone.  Adobe ended support for MX ages ago.  Besides, nobody should be using outdated software on the modern web.  Too much has changed in 18 years. 😮

MODERN CODE EDITORS:
-- Adobe Dreamweaver CC - https://www.adobe.com/products/dreamweaver.html
-- Atom (free) - https://atom.io/
-- Codespaces (free, browser-based) - https://github.com/features/codespaces
-- Nova (Mac only, formerly called Coda) - https://nova.app/
-- Pinegrow - https://pinegrow.com/
-- Sublime Text - http://www.sublimetext.com/
-- Visual Studio Code (free) - https://code.visualstudio.com/
-- Wappler ~ Visual Web App Builder - https://wappler.io/

============
ONLINE SITE BUILDERS:
-- Adobe Behance (free) - https://help.behance.net/hc/en-us/articles/204483894-Guide-Intro-to-Behance
-- Adobe Portfolio (free with a paid Creative Cloud Plan) - https://portfolio.adobe.com/
-- Squarespace - https://www.squarespace.com/
-- Webflow - https://webflow.com
-- Wix - https://www.wix.com/
-- WordPress (open source) - https://wordpress.org/

Hope that helps.

Sorry MX 2004 is dead. It cannot be activated any longer, the activation servers were laid to rest some years back. The only way forward now is to join the Cloud subscription if you wish to use Dreamweaver, which I personally think is a waste of money and time as DW is only minimally maintained now. You're better off seeking other solutions that are still being actively developed if you just want a paid-for web-editor solution.