Can't open Norton 360

decided to down grade back to windows 7 after not enjoying Windows 10 and now cannot open or locate Norton 360 premier when trying to open get the same dialogue box: C:\Program Files (x86)\Norton 360 Premier Edition\Engine64\21.7.0.11\uistub.exe Unspecified error.

How do I uninstall and reinstall? will not let me uninstall through control panel