If you already have Internet Explorer 7 installed you might be interested in Multiple-IE . An installer for the standalone versions of IE6, IE5.5, IE5, IE4 & IE3!
First I would like to apologize to those who tried the previously published Steps and missed up their IE6. Running IE7s.exe should fix everything for you.
Internet Explorer 7 is here! Microsoft officially released IE7 to the public after almost a year and a half of public beta testing.
The way in which we can run the release version of IE7 in standalone mode (side by side with IE6) hasn't changed much. Perhaps the only change is that without the launch program (in other words without the registry entries) IE7 auto-registers all the dlls that came with it rendering IE6 useless.