Windows XP's share of the operating system market saw its biggest drop since January last month, with Vista picking up its biggest number of PCs in ten months.
Net Applications, which monitors computers connecting to 40,000 websites to establish market share and trends, said XP lost 1.81 percent of the market during November, with Vista growing by 1.16 percent. The web monitoring firm also said Windows dipped below 90 percent of the market for the first time.
Vista's increase enabled it to surpass 20 percent of the OS market for the first time, ending November at 20.45 percent.
Meanwhile, Microsoft's ageing Windows 2000 OS fell to 1.56% of the market during November, while Linux achieved 0.83 percent - up from 0.71 percent during October.