Apple's share grew to 9.93 per cent in January, as Windows fell to 88.26 per cent. In addition, the iPhone operating system was used by 0.48 per cent of users.
Net Applications reported strong interest in Windows 7, meanwhile, which Microsoft released as a beta on 9 January. The beta was so popular that Microsoft had to suspend its usual download limits on the software.
"This is an indication of strong interest in Windows 7, since it does not come pre-installed on a computer, like Vista," said Net Applications.
"Beta users are taking the time and effort to install it on their home computers, since corporations generally prohibit beta operating systems in production environments."
The Net Applications data was not such good news for Linux distributions, however. Fewer than one per cent of computer users have Linux installed, despite an upturn with the growth of the netbook market.