IWas the trial the home or enterprise version if home run the removal tool below
Have you removed the trial try MCPR to clean up the install It may remove Mcafee browser protection which is another name for Site Advisor I think
If the browser protection is corporate version 5.2 read this
McAfee is a good program. When you are successful removing the trial version (I think that you can just enter the new # of the product you purchased to upgrade/activate Total Protection) install the program you bought. I have used it for 3-4 years and it is better than any of the other premium programs and far superior to any free program out there. Hope this helps.