Uninstall the application, reinstall it. Also download the update manually from the Adobe site. Without knowing anything about your system, it doesn't get any more specific than that. And please ask such questions in the product specific forum next time.
Thanks, I will try that. I just installed 9, I have a HP i5, 64 bit laptop. I also have LR3.6 and PSCS5.1 installed on my laptop.