Installing Exchange 2000

OK, i downloaded the trial version from MS. I installed exchange on my PC whihc is acting as the PDc and DNS (i only have one PC that can handle these stuff at the moment). Anyways, i seem to be missing something. i start the administration program for exchange, and its asking me for the mail server. i thought i installed it on the PC? I pointed the thing to the PC’s address, and it still didnt work. Is there a setting I have to configure? i managed to install IIS on the same system w/o a hitch