The infection rate of Windows Vista SP1 was 61.9 percent less than Windows XP SP3, the company said. The report covers the first half of 2009 and is the seventh such twice-yearly report the company has issued. Windows 7 was not included in the report. For all Microsoft operating systems that the most current service pack is always the least infected, based on infections per 1,000 computers running each OS, the study found. Read the full report [Network World],.
Source: https://threatpost.com/microsoft-vista-infected-62-less-often-xp-110309/72997/