Summarize:

https://www.adobe.com/cfusion/tdrc/index.cfm?product=flashpro. Follow the instructions provided for download and installation - you will have to create an account. Locate and double click the files to launch (if they haven't launched automatically already). Follow the on-screen instructions to extract the files to your desktop. exe Follow the instructions to install CS3.
Download Adobe CS3 here: Launch the executable files. Extract the files. Launch Setup. Finish installation.