You can also get rid of IE by using this method
Start > Control Panel > Add or Remove Programs > check the box that says 'Show Updates' (it is at the top right corner of the Add or Remove Programs window, and you only need to do this for the previous version of IE). Then click on the 'Remove' button under Internet Explorer 7 Beta 2 Preview (if this is the version you are talking about).
Just uninstall it and restart your computer.