"Finally, Macs are much safer than Windows PCs on networks and the Internet. This last advantage is more important now than ever before, with virus counts in the millions and spyware literally sprouting out of every corner of the Web.
These are important advantages, but only the third one, the issue of safety, could be considered a deal-breaker. In the many weeks that I used my Windows 7 laptop for daily computing tasks, I was very much aware of the dangers lurking on the Internet.
I tried three or four different antivirus and spyware-detection suites, but still lost all connectivity when a virus knocked out my PC’s networking. I had to reinstall Windows 7 from scratch.
This simply doesn’t happen on a Mac. As attractive as Windows 7 is, it remains in Apple’s shadow in the crucial area of Internet safety."

Windows and Malware
David (OFI)