When a user upgrades Parallels Desktop, he is asked if he wants a free six month subscription to Parallels Access. Even if he says no, the product is installed on his system and the application is started each time the system is rebooted. It is installed with ancillary files scattered around several directories in the system and Parallels has not supplied an uninstaller or listed the steps to fully uninstall the application, despite a number of requests.
In other words, Parallels has decided it's a good idea to silently install a difficult to remove deamon application on the system, even if the user has explicitly stated they do not want it. They have not provided an uninstaller or a list of files installed or instructions on how to remove the application files. These are scattered to at least four Mac OS X OS system level directories.