It should be in your Add/Remove programs but if it's not, we'll presume you're using IE8 and go from there so we can at least disable it.
1 - Enable IE8's toolbar. To do that, right click on IE8's toolbar and enable 'Menu Bar'.
2 - Go to the 'Tools' menu and select 'Manage Add-ons'.
3 - Select/Hightlight BING Tool bar and click on 'Disable', in the lower right.
Close, re-start IE8 and you should be all set.
Like a lot of people Don't Use IE use Firefox or something else