Adobe Dreamweaver CS3

CS3's activation servers were taken down some time ago.

You can still install and activate the program, but there are some steps you'll need to take to do it. Basically you'll be logging in to a special CS3 page with your Adobe Id, downloading an offline activated version of the program using your current activation code, then installing that using a special offline code given by Adobe...

To install CS3 or Acrobat 8, go to this page...

https://landing.adobe.com/en/na/products/creative-cloud/ctir-2113-exchange-serial-number-cs3-4.html

...and follow the instructions given here...

https://forums.adobe.com/thread/2385900