Pete, try AVG it is very good.
Also, i know this doesn't help with this particular problem but can i suggest that from what i know about you already some games or other kinds of sites aren't safe, and sometimes it's hard to know where is safe and where isn't when you are a novice, so i highly reccomend this plugin for your browser, if you use Internet Explorer use the link on the right and download it. It shows sites as being green (safe) or red (unsafe) on google searches.
http://www.siteadvisor.com/download/ff.html
Try it, it's very easy to use, i use it myself and it is brilliant
