As you known by all, Internet Explorer 10 is the default browser in Windows 8 (launched a few months ago). It has substantial improvements over previous versions of IE and complies all the new web standards (HTML5, CSS, etc.). IE10 is now much lighter and faster than previous versions.
Note that, unlike the Windows 8 version of Internet Explorer 10, the browser on Windows 7 does not come with an Adobe Flash plug-in pre-installed. You need to install flash plug-in separately for better performance of flash contents.