Still Cannot Access Root Drive ( C:\ )

I need to copy a file into my Windows 10 root drive (C:\). I cannot and get Error 0x80070522.
- Found a tool which I really don't want to use since it is for folders and sub-folders.
- Turned off User Account Control setting is set to the lowest.
- I don't have HomeUsers account in my Group Or User Names, Security Tab.
- The PC is my personal system.
- My PC at work has UAC security bar at medium and can still copy a file to my OS root drive.
So, how can I have access to my home PC's root drive (C:\)?
Thanks.

You need to be running as an administrator to be able to do this and provide the permission at the UAC prompt. If you do this and it still does not work your account may be corrupted in some way. You could test this by creating a new account and seeing if it will work.

It works for me in WIn-7, but not in Win-10. Error 0x80070522
I have a file in the root directory that I need to update during the start-up of the system. I can not place it in a user folder because at that time I don't know which user is signing on. The process runs no matter which user is signing on. The file created is read by a process on another computer, so it needs to be at a specific location.
How can I change the security so that I can access these files?
Help.
(I am not having fun with Windows 10, or the change from WLM to Outlook 2016, but more on that elsewhere)
Ernest