Windows 7 appears to have gained market share. On the other hand Windows Vista & Windows XP have lost market share in September 2009; Vista, for the first time in 2 years.
According to Web metrics firm Net Applications, Vista dropped 0.2 percentage points during September to end the month at an 18.6% slice of the operating system pie. It was the first decline for Vista since a 0.3 percentage-point slip in January 2008.
The share of Windows 7 is expected to increase further, after its official launch this month.
Windows Vista will have peaked at less than a 19% market share, and at its most popular, accounted for only one-in-five Windows machines.
In comparison, Windows XP, Microsoft’s eight-year-old operating system, accounted for 71.5% of all operating systems powering computers that connected to the Web last month, and ran more than three-fourths of all Windows PCs.