I don't know if this is the right forum, but this is where most people seem to ask if it's possible to install several versions of IE at once.
I didn't think it was possible until I came across this in today's access magazine, published weekly in many US newspapers and available on the Internet at http://www.accessmagazine.com.
This except might interest most of you here:
You can keep multiple versions of Internet Explorer for Mac on the same machine in different folders. IE for Windows is a bit trickier. Before version 5, it wasn't possible to have multiple versions running on the same computer. With IE5, Microsoft introduced "compatibility mode", which allows you to view a Web page with versions 4 and 5. Microsoft has full details online at http://support.microsoft.com/support.../q197/3/11.asp.
I haven't tried it, but it's worth a look.