After uninstalling McAfee I realized that there are some files left in Common Files folder. I have already used the MCPR tool, it removed some files but not all of them. When I tried to delete them, it said that I need permission from Administrator, but I am admin. Take ownership didn't work. So anyone have any ideas to removed those files completely? Thanks in advance.
Try rerunning the mcpr tool I assume you have rebooted after it was run? Sometimes a second run clears up the missed files. that said this was a new mcpr download I assume if not download a new copy.
Step 2: Download and run the McAfee Consumer Product Removal tool (MCPR)
You should only use the MCPR tool if the Windows removal methods shown above do not work.