Yes, turn it off
In its place use Microsoft Security Essentials and Malwarebytes. Less resources used and they are really good. http://www.malwarebytes.org/mbam.php
These two pieces of software are used by many of the members, in addition to myself.
All you need is a firewall, anti virus and malwarebytes, everything else in Mcafee, is not needed.
To turn if off, go to search type in msconfig, go to the start up tab, untick mcafee. Turn off the computer, boot up and now it is not on. If you no longer want it you can uninstall, now, from the control panel in programs
If you want to know how to maintain your computer, just post and I will be very happy to help.