My Mother's Norton Gold version 21.3.0.12 has killed her IE 11

My aged Mother (not here so I can say that) has a note book running IE11. She also has Norton 360 claiming to be product version 21.3.0.12.

Some months ago she stopped getting access to any websites through IE after receiving a warning about (to quote her) "someone might be trying to access your account". She was in Spain at the time using a neighbours security enabled Wi-Fi.

Since then though she can open IE, however regardless of what website I or she (or even her techie grandchild) does we get the same message "this page cannot be displayed". Her machine connects to the UK Wi-Fi fine and sends/receives emails happily.

Having done some research via my laptop I have seen suggestion's that there might be a conflict between Norton and IE and the thing to do is uninstall Norton, return IE to factory settings and reinstall Norton.

The first problem is that I cannot open Norton from either the desk top icon, the start menu or even the "all programs". It either ignores me (the first two) or comes up with an error message "C:\Program Files\Norton 360\Engine\21.4.0.13\uistub.exe". This happens regardless of which of the options the Start page gives me (Open, Rub Quick scan etc.)

In addition I got a "Norton Autofix" page pop up saying "Norton 360 has encountered an error, Error 8504,104". Then "Repair -Live Update, Result - Failed" with the instruction "open support Web Site" which of course failed.

I then went online and found this forum and found a thread with exactly the same error message. The solution seemed to be based around going on line, which of course I/she cannot. I tried uninstalling it through the control panel and it ignored me. Incidentally when I highlighted it it said Norton 21.3.0.12 which I notice is not the same version as the error message.

I am loathe to go into Windows Explorer and delete from there so I was wondering if you could help my silver surfer Mother who is desperate to get back on line and cannot.

Thank you in advance

P.S. simple words please would help her and me

PPS attached is a screen shot of the two error pages