For the most part Microsoft hasn’t made it very easy for people who want to run multiple versions of Internet Explorer on their machine, which can be difficult for web developers who need to test sites against older versions of the browser. A new tool, however, called Internet Explorer Collection will let you pick and choose which versions you would like installed on your computer.
Once you being the installation process you’ll be prompted with a screen similar to what you see above. Versions of Internet Explorer that are not compatible with your operating system should be automatically disabled just like how IE 1.0 is since it’s running on Vista. Similarly you can also checkout the homepage of the software to see a chart of which versions of IE are compatible with your operating system before you even try to install them. Sorry to break it to you, but no operating system will work with all versions of IE that are bundled in the app.
Internet Explorer Collection is frequently updated, and even includes the latest IE 8.0 Release Candidate 1 build. Just be careful… once you start using Internet Explorer 1.5 you may not want to go back to anything else. :)
Get Internet Explorer Collection for Windows