First of all, doom IE for LIFE. I seriously hate it and I think it is deprecated.
BUT a lot of people still use it so here we go. Is there, in any sad way, a method to use IE6, IE7 and Firefox on the same machine. IE7/IE6 AND Firefox arn't a problem, but IE6 AND IE7 is not possible, for as far as I know. Installing a virtual server on the other hand is somewhat stupid.