Hi alocksley: When I last found myself in a similar situation, I made sure that I did not activate or register the McAfee that came pre-installed on my system. - I downloaded my preferred AV to my desktop.- I uninstalled McAfee via Control Panel.- I downloaded and ran the McAfee uninstall tool (MCPR) from their website, according to its instructions:service.mcafee.com/FAQDocument.aspx;lc=1033&pf=1This tool cleans up the remnants. I note that the instructions now say you should activate your McAfee subscription before uninstalling them, if they came pre-installed. I would follow these latest directions, as it has been a few years since I addressed this issue.- I installed my preferred AV. Good luck!
Awaiting my new Dell Inspiron 7000 which, unfortunately, comes with McAfee AV.  Been a loyal Norton user for many years, so the first thing to do will be to uninstall McAtee and install Norton. Are there any "gotchas" about uninstalling McAfee, given that it's built into the shipped system? Or is it just "control panel/programs/uninstall" or whatever the Win7 equivalent is in WIn8.1? Thanks. BTW I asked this question of Dell's chat while I was configuring my system for purchase and they offered up a link to a McAffee website that was supposed to explain removal, but the link was dead. 
Removing McAfee from an new machine