Branched to a new thread as it has nothing to do with that 2 years old thread you posted to.
You have inadvertently installed McAfee Security Scan Plus which is not a scam by any means, simply as tool to check what security software you might need. It is offered optionally with such things as any Adobe product (Flash, reader etc.), so all you have to do is go to your Programs list in Control Panel and uninstall it.
As Ex_Brit stated, one has to pay close attention to the (Optional Offers) included with Downloads. Especially With Adobe Flash Player, which includes Norton/Google Chrome and others. So it is not McAfee alone...
You may find the following article most informative : How you get tricked into installing Potentially Unwanted Programs
McAfee Volunteer Moderator