I was asked this question recently and it is a pretty easy thing to do in Internet Explorer 9.

If you don’t want your tabs to show up next to the One Box (where you see he URL of the site you are browsing and search from)

IE9 one box

Simply right click anyway right of the new tab button and select Show tabs on a separate row

Show tabs on a separate row

and now you should see your tabs underneath the one box

tabs under one box in IE9

Change the location of tabs in Internet Explorer 9

Rob