I downloaded and ran the AAM8 that that link, but have CC installed so it stops before it gets very far so I don’t see that message you’re getting.
Here is another page that lists three solutions, the first being the same AAM download but then two others:
http://helpx.adobe.com/creative-suite/kb/error-application-manager-needed-cs5.html
You might also check the install logs:
http://helpx.adobe.com/creative-suite/kb/troubleshoot-install-logs-cs5-cs5.html
Here is a longer help article about AAM problems:
http://helpx.adobe.com/creative-suite/kb/troubleshoot-update-issues-cs5-cs5.html
I wonder if you should uninstall everything Adobe and then run the CC Cleaner to clear out as much as possible, then reinstall CS5:
http://helpx.adobe.com/creative-suite/kb/cs5-cleaner-tool-installation-problems.html