Windows 10: Can't save file in C:\ root directory

Not quite, you are an administrator (a member of the Administrators group) not the Administrator. That honour (and unrestricted access) belongs to the built-in Administrator account (which for good reason is disabled by default).

 

The built in administrator account should be reserved for when you really need it. For most people that will be never. Using the account is a security risk and you will also find some things, such as modern Apps, will not work. This is by design.

An added problem with giving other users access to the root of C is that it doesn't stop there. Any folders that are now added to the root of C will by default inherit these permissions, as will any subfolders and files. This is not a good thing. Any previously existing folders and files will be unaffected.

 

Like I said, this is made that way to protect you from yourself. But if you have to absolutely save the file there then enable the admin account because yes even though your are an admin your are not THEE admin. Save the file then give your regular account read write modify permissions.

 

All is fine now!

I restored my C: drive to a backup that was done on 9-1-16 that has the Win 10 Anniversary update.
Which reset all my security permissions back to Win10 defaults.

I use Acronis TI2016 to perform backups. I exclude backing up the following files.

hiberfil.sys
pagefile.sys
swapfile.sys
System Volume Information

After the restore these 4 files need to rebuild themselves.

Well I can now copy/move any file to the C:\ root directory with ease, I get the popup window asking for administrator permission, hit continue, and the file shows up.

Something got reset in the restore processs.

All is good! Thanks for all the suggestions and help.