Solution 1
If you want to run Multiple Versions of Internet Explorer (7,6,5.5) in Vista/XP for your testing use IETester.IETester is a free WebBrowser that allows you to have the rendering and javascript engines of IE 6 and IE5.5 on Vista and XP, as well as the installed IE in the same process.
Minimum requirement : Windows Vista or Windows XP with IE7 (Windows XP with IE6 has some minor problems)
Known problems and limitations
When resizing, the content may disappear. I am working to correct it on the next version.
The Previous/Next buttons are not working properly
Context menu is not working
Focus is not working properly
Currently this is This is an alpha release.
Download IETester from here
Sample Screenshot

Solution 2
Another way of running Multiple Versions of Internet Explorer by installing virtualPC,Vmware or Virtualbox softwares.
Solution 3
Using Multiple_IE (IE Versions 6,5.5,5.01,4.01,3.0)
This will work only in XP
Download Multiple IE installer from here
Incoming search terms:
- multiple ie windows 7 (10)
- run multiple versions of ie (6)
- how to run multiple versions of ie (3)
- multiple ie on xp (2)
- multiple ie windows xp (2)
- multiple internet explorer versions windows 7 (2)
- multiple versions of ie vista (1)
- win xp multiple internet explorer versions (1)
- multiple versions of IE windows 7 (1)
- multiple-ie (1)
This is a absolute fantastic (c)tooooool!!
Great.
Thank you
This is a very great tool! Thank you very much for this!
Great idea, but unfortunately doesn’t quite cut it. My site in IE 7 is screwed up when I know it display fine in standalone IE7. Loading it in an IE6 window crashes IETest.