You can find the version by clicking on "Help" "about" up the top. (Expect it to be IE7 or 6) (Personally I prefer IE7, it's a bit more secure and has tabbed browsing.)
Firefox I'm liking, partly because there are a large selection of "add-ons" easily available for it. Some of the more popular include Ad-block plus, and Noscript. Useful.
What security software do you have (a) running and (b) available for demand scanning?