you'll need to analyze your installation logs: http://helpx.adobe.com/creative-suite/kb/troubleshoot-install-logs-cs5 -cs5.html
if you can't work that out on your own, you can contact adobe support: http://www.adobe.com/support/chat/ivrchat.html
you'll need to analyze your installation logs: http://helpx.adobe.com/creative-suite/kb/troubleshoot-install-logs-cs5 -cs5.html
if you can't work that out on your own, you can contact adobe support: http://www.adobe.com/support/chat/ivrchat.html