Be careful about who the email is from. It is easy to spoof email headers and for that matter IPs. If you want updates from microsoft go to microsoft.com and get them. Also we did extensive research and lab testing of many of the virus protection products on the market, our tests showed Computer Associates to be the winner. It caught every test virus including in the wild mutations we created for test purposes. It also had one of the lowest performance impacts. Best of all its cheap compared to the rest of the bunch. You don't allways get what you pay for.
Another great way to protect your system is by proactive monitoring (IDS). Finjan corp. (
www.finjan.com) produces a terrific product for personal use : SurfinGuard Pro. It does not rely on signature tables that need to be updated, rather it is a policy based system that monitors all downloaded active content (Executables, Java Applets, Javascript, Vbscript, Macro, Etc). When any of these are downloaded, with or without your permission or knowledge, it isolates, and runs them in a protected sandbox. Should the content break policy, it will shut the process, thread, or fiber immediately. It comes with a set of rules that will work for most people, but of course can be configured by the user. It does impart a small performance hit on the system, but its not that noticeable unless you are running an older system, and even then it is tolerable.
Lets be carefull out there !