The Internet Explorer team has updated the installer for IE7. Mostly they've adjusted a few defaults and updated their tutorials, but one change stands out: The installer no longer requires Windows Genuine Advantage validation. Almost a year after its release, IE7 has yet to overtake its predecessor. Was WGA holding back a tide of potential upgrades, or did it just send people over to alternative browsers?

http://blogs.msdn.com/ie/archive/2007/10/04/internet-explorer-7-update.aspx