How can I uninstall Norton Family if my account details are missing?

Dear Support at Norton Family,

Sorry to bring this subject up again as I've already seen that it's been discussed here before, but I'm just not getting anywhere - none of the advice I've found here has worked so far, meaning I can't uninstall Norton Family on my son's computer.

The crux of the matter is that I've mislaid the account details I used to set up Norton Family, so I can't change the original settings I made and I can't delete the program either. I've tried installing the latest version of Norton Family on it and then uninstalling the program, which you advised someone else to do once, and I've tried deleting the folder stored in Public/Public downloads, but whenever I try and uninstall NF from "Programs and Features" (in Windows 8.1), the program just asks for my details again. But my user details have got lost and I'm stuck as a result.

Changing the log-in details for the several Norton accounts I have hasn't helped either as the program just keeps on telling me different account details are needed. Is there any way of uninstalling Norton Family without having to key in account details, please? Apart from deleting absolutely everything on the computer by re-installing Windows 8.1 (and then having to install my son's best programs again)? Please say yes and tell me the secret...

Hope you can help.

Carl