BBC News: Two million US PCs recruited to botnets

Despite the large number of people being caught out, Mr Evans said that defending against malware was straightforward.
He said people should sign up for automatic updates, make sure the applications they use are regularly patched, use anti-virus software and run a firewall.
Microsoft has just issued its largest ever list of fixes for flaws in Windows, Internet Explorer and a range of other software.

Or… stop using Windows. Why do people put up with this crap?