Don’t bother with the GUI. This will delete the Program Files directory, etc.
1. Launch and Administrator command prompt: CMD w/ Ctrl-Shift-ENTER.
2. Take ownership and change permissions. e.g.
takeown /f "program files" /r /d n
icacls "program files" /grant administrators:F /t
3. Delete with impunity.
In my case, there were a couple of straggler files with explicit DENY permissions enabled. Thanks, Adobe.
In order to delete Flash11c.ocx, I had to manually right click the file, go into Properties, Security, Advanced, Change Permissions, and Remove the explicit DENY permissions on the files.