I had already did all this before posting my question and I still get this error message when I try to install a new version of Flash Player.
Well, "administrator rights" is a Windows requirement.
Download this file: Take Ownership.zip
Double click it.
Click Yes, and OK.
Then, open Windows Explorer to your Computer.
Right click the C drive and select "Take Ownership".
It'll apply owner permissions for your account to the entire contents of the drive. It'll take a while, but when it finishes, you'll have full access to read & write any file on the drive.
Thanks, Mike! It worked!!