The launch of Windows 7 in October did nothing to stop an increase in Mac share online, the latest data from Net Applications shows. Although the Microsoft OS was on sale for nine days last month, Windows' combined share of Internet traffic actually dropped to 92.52 percent while Mac OS X profited directly, reaching a new high of 5.27 percent. Windows 7 did gain share and represents 2.15 percent, but its gain was more than offset by a full percentage point of Windows users abandoning Windows XP, in many cases opting for the Mac or other platforms.

It's unclear whether the trend will continue. Microsoft chief Steve Ballmer himself expected little direct help from Windows 7 in the short term as most users are only likely to buy Windows 7 pre-installed on a new PC rather than as a mid-cycle update from XP or Vista. The necessity of wiping a system clean to upgrade from XP to 7 also creates a barrier that Apple has exploited in ads, claiming that users may as well switch to a Mac if they need to start from scratch.

The Windows developer also reached a new low in web browser traffic in October. Internet Explorer dipped below 65 percent for the first time to reach 64.64 percent, while Firefox has climbed to 24.07 percent. Chrome and Safari also made gains in the period, increasing to 3.58 percent and 4.42 percent as they stole share from Microsoft.

Operating system market share, October 2009
 

Web browser market share, October 2009