The Internet Explorer listing in the Windows Components section actually only enabled/disables the default shortcuts on your desktop and in your Start Menu...it doesn't control whether or not IE is installed. (That's why the reported file size is 0.0MB despite the fact that Internet Explorer is around 15MB in size.)
That said, when you install Internet Explorer 7 it will replace IE6...you cannot run them side-by-side and switch back and forth. However, you can return to IE6 at any time by uninstalling IE7, which will restore the former from backup.
Hope this helps,
Running Windows XP Pro SP2.
One question on installing IE7: IE6 is at Add/Remove Windows Components. Will installing IE7 replaces it with the new version, or will IE7 be treated as another program ? Thanks.