I'm successfully running One Care on a laptop with Vista operating system. In an attempt to install One Care on my desktop, I uninstalled BitDefender 2009. I get Error ID: 0018-80070643. I have followed the steps outlined in the help screen. During installation of Microsoft XML Parser, I get an error message "An error occured while attempting to create the directory: C:\Program Files\Common Files". It gives Retry and Cancel options. The Retry does not lead anywhere. What could be the problem?