Brendon.
You can download a 30 day time limited Trial version of After Effects CS4 here. After 30 days it will cease to function without a CS4 serial number, which you cannot purchase now if you don't already have one.
http://prodesigntools.com/download-adobe-cs4-and-cs3-free-trials-here. html
Ensure that you follow the Very Important Instructions on that page first otherwise the links will not work.
You can no longer purchase After Effects CS4 and it definitely is not available for free even though it's a superseded version. So you'll only get 30 days out of it.
I take it you're trying it because you have a 32 bit system?
Thanks, but none of the downloads are working. I just tried clicking the download trial version and it says
RequestURI=/support/downloads/dlm/main.jsp
It's not downloading anything. Are the servers down or something? Thanks for the suggestion anyway.
Thanks, now I was able to download it, but when I extracted the files it has another error, saying "Critical errors were found in setup for adobe after effects cs4: the installer database is invalid: please re-install from the orriginal media please check the setup log files for details..." any idea what caused this? I looked and followed all the directions from 0 to 6, and followed the product installation instructions. So what did I do wrong? Can my computer not handle this version either?
run the cs cleaner in case you tried previous installs: http://www.adobe.com/support/contact/cscleanertool.html
restart your computer and then try installing.
North America
Europe, Middle East and Africa
Asia Pacific