"... Microsoft announced on Monday that its anti-malware service aimed at offering consumers protection against viruses, spyware and other malicious software, dubbed Microsoft Security Essentials, would become available for download from the company's website starting today, September 29, 2009. "
About time they released something like this, should really be a default install with windows. I've heard good things about it, going to replace my trusted AVG Free with it today.
Will work on XP, Vista, Win 7.
Download is live .