If you are using the latest Firefox you might be knowing that that you can undo an tab close action by pressing Ctrl+Shift+T to reopen the closed tab.But the same is not possible in Internet Explorer 7, you can have this function in IE 7 by installing IE7 Open Last Tab Add-on.After installing just hit “Alt-X” and the accidentally closed page automatically reappears in a new tab. If you hit “Alt-Q” instead, the add-in will display a Quick Tabs Style View, of the recently closed tabs. Click on one of the thumbnails from the view, and the page will open in a new tab.

Download: IE7 Open Last Tab Add-on | 224 KB