Loss of Norton Scan Facility on right mouse click on downloaded file

I normally check for threats in downloaded files by right clicking on my mouse and NS360 used to appear in list of options. Since reloading renewal from a disc the option appears to have disappeared. Any ideas please where it is gone or how to put it back in so I can just check one highlighted file. Alternatively where is the option in the main NS360  4 Box Main Menu to choose one file to scan. Thanks for any help. DJS