The interface of Internet Explorer 9 RC is nearly identical to that of the IE9 beta. Its minimalist window leaves more room to the webpage contents than any other new browser, keeping controls to a single row and combining the address and search boxes into one. If you don’t like the new interface, you can still enable IE’s menus and toolbars, by right-clicking on the top window border.
Tabs have been improved not only visually but also with an option to move them below the address bar of the web browser.. IE9 lets you drag tabs out of and back into your browser window to create new windows, as other browsers have done for a couple years. You can now place them on their own row if you find you’re opening too many to fit. The tab with the focus is now brighter, making it stand out.
Microsoft has implemented features that another browsers has like one box for search and go to web address, pinned sites, smart screen features, and another new features. You can check another features here
Microsoft has revealed that it plans to upgrade Internet Explorer 9 Release Candidate (RC) users to the final bits automatically when they are available later this year.
If you want to download offline installer, please check from Windows 7 News