Microsoft's much-maligned Vista operating system has started to lose market share to its replacement, Windows 7.
Windows 7 has not yet been officially released, but is already making an impact, according to web metrics firm Net Applications, which said that Vista lost 0.2 per cent share during September to end the month with 18.6 per cent of the operating system market.
Windows 7 gained 0.3 per cent, according to Net Applications, representing its biggest monthly gain since Microsoft began making it available to developers and other specialist groups at the beginning of the year.
Even if Microsoft has not yet received any cash for Windows 7, it apparently powered 1.5 per cent of computers that connected to the subset of the internet monitored by Net Applications last month.
Microsoft will release the full version of Windows 7 on 22 October.
However, while Net Applications' figures may represent a bit of good news for Microsoft, it also shows how bad Vista was for the firm.
Vista managed to gain only 19 per cent market share in its entire history. Windows XP, Microsoft's eight-year old operating system, accounted for 71.5 per cent of all operating systems that connected to servers monitored by Net Applications last month.
Windows XP has also been losing ground for two years, but Microsoft still holds 92.8 per cent of the market, according to the figures.
Apple's Mac OS X climbed by nearly 0.25 percentage points over the past month, to end up with a market share of five per cent of all machines monitored by Net Applications.