Your experience with Windows XP and Vista is telling you there's no way you could remove IE completely in Windows 7? Surprisingly, you're wrong.

This FAQ explains step-by-step how to uninstall Internet Explorer 8 from Windows 7 completely:

1. Open Windows 7 Control Panel
2. Navigate to Programs > Programs and Features
3. On the left-hand sidebar click Turn Windows Features On and Off
4. Uncheck the Internet Explorer 8 option and click OK
5. Confirm your choice in the next pop-up window
6. Click OK again and IE8 will uninstall completely

Your computer needs to be restarted for the uninstallation to complete.