Out with the old and in with the new appears to be the theme for September. It doesn't even matter that Windows 7 hasn't been officially released yet, the Release Candidate has been solid enough for Vista users to leave their old OS behind and rock out with Microsoft's newest darling, according to market share data by web metrics firm Net Applications.

Vista's market share dipped by 0.18 percent in September, which isn't earth shattering, but it is the first time the OS has back tracked since January 2008. Windows 7, on the other hand, climbed 0.34 percent and now claims 1.52 percent of the market. Not bad for a pre-release OS.

On the browser front, Internet Explorer fared a little worse, losing 1.26 percent of its market share. The continued backwards slide has to be troubling for Microsoft, especially considering IE's market share set a new low of 65.7 percent. That's good news for Firefox and Chrome, whose market share jumped by 0.77 percent and 0.33 percent, respectively.