Without going any further into troubleshooting, I suggest uninstalling then running the Adobe Cleaner Tool
http://helpx.adobe.com/creative-suite/kb/cs5-cleaner-tool-installation -problems.html
Then reboot and reinstall CS5.
Without going any further into troubleshooting, I suggest uninstalling then running the Adobe Cleaner Tool
http://helpx.adobe.com/creative-suite/kb/cs5-cleaner-tool-installation -problems.html
Then reboot and reinstall CS5.