Free Mcafee VirusScan Plus 2008 1 year subscription
Go to http://www.natwest.com/microsites/personal/latest_deals/index.asp
Click the Free PC security banner done towards the bottom of the page.
Click the register now button on the resulting page.
Sign in or create a mcafee login and presto.
It seems you can only get to the McAfee link through the natwest.com link above but if that link goes down, you can try the direct link at http://uk.mcafee.com/root/landingpages/afflandpage.asp?affid=540&lpname=vsf
Also the site seems to be having issues. Too much traffic I would think. If you get runtime page errors try again at another time.