By default everytime you open a new tab in Internet Explorer 7 the url displayed is about: blank. You can modify a setting to make a new tab open as your home page instead of blank.
In IE 7 navigate to Tools->Internet Options
In the Tab section , click Settings button
Check "Open Home page for new tabs instead of a blank page"
Click New Tab (small tab next to current tab)
At the bottom of the page check the box that says "Don't show this page again"
Now everytime you open a new tab it will be your home page