This struck me---
"I would suggest, enabling the Administrator account (normally hidden / disabled)....
BUT
As the entry is to HKEY Current User, it wouldn't be present in the same place you currently associate with it.
You'd have to go find it in HKEY Users, which you and in-fact a lot of people might find daunting."
If I find the key in HKeyUsers, would editing THAT one do the trick, or do they both need edited?
I did do all of my efforts so far under Administrator account... At least I believe I had.
Even in that, I was unable to edit rename or delete