For those that had the same problem I did, the IE7b3 installer complaining that
Internet Explorer 7 is already installed on this machine, despite the fact that I uninstalled beta 2 from the
Add or Remove Programs Control Panel without error (though clearly far too fast to have actually done anything), simply follow these instructions:
- Delete or rename C:\Program Files\Internet Explorer\iexplore.exe.
Now the installer will work fine.