Hi there,
Some keys are protected by a trusted installer. You have to set yourself as the owner of the key first and give yourself full writing permissions.
Regedit, select your key, right-click-->Permissions-->Advanced-->Owner, select Administrators, Apply. Then grant full control to "System", and, if you like, to "Administrators" also.
The below thread discusses the same issue and you can try out some troubleshooting steps from this and see if that helps you to sort the Issue.
-------------------------------------------------------------------------------------------------------------------------------
--If the reply is helpful, please Upvote and Accept it as an answer–