On January 8th, Tony Chor, Group Program Manager on IEblog wrote that IE 7 had reached 100 million installations, bringing the stats to over 26 percent of all web surfers using Internet Explorer 7 according to WebSideStory with IE 6 not far behind in second place.

The milestone comes only a few months after the release of the browser upgrade, and still seems to be quite a feat despite the fact that IE 7 became a critical update not long after it’s launch. Mozilla’s Firefox, which many believe to be the number 2 browser is continuing to gain popularity but took almost a year to reach the same milestone. Firefox is certainly not going to let IE gain too much ground as they have a new version of Firefox coming soon.

Internet Explorer 7 was launched by Microsoft in October of last year and came with some advanced security to aid against malicious software and phishing attacks. The IE 7 browser also came with tabbed browsing which allows multiple sites to be opened on the same browser in separate “tabs”.

“We expect these numbers to continue to rise as we complete our final localized versions, scale up AU distribution, and with the consumer availability of Windows Vista…”, said Chor on IEBlog.

The launch of Windows Vista to consumers will most likely increase the number of surfers using IE 7 since Vista ships with the newer version, although according to NetApplications IE 7 has yet to cut into Firefox’s market share. IE 6 has been taking the hit so far, likely due to upgrades.