I have read the posts here on this site but they do not work for me. The post number ID: 22692068. I also tried the post from http://sbs.seandaniel.com/2006/02/using-microsoft-exchange-server.html
That does not work. The install keeps creating a new default site and stops my main one. I have spent 3 hours on this installing and uninstalling. Changing the Directory Security AFTER the install does not change the fact that a new default site was created. I am running SP2 on SBS 2003.