You could try going to the Control Panel, you can write it in the search field next to the Windows menu and it'll pop up. There open Programs (Uninstall a program), active Freedome on the list by clicking it and then hit the Uninstall text in the header.
The tool uninstalls all F-Secure products you have on your computer when you run it or can you choose which one(s) to uninstall? Just a thought as he had already installed the new app.