Microsoft Exchange Server 2003

[NewbieIT]

I need help with microsoft exchange server 2003. I installed mses 2003 on my the network server and created 2 test e-mails to try out exchange with before I completely migrated the e-mail accounts to exchange on the network server. I had problems with the test e-mails, they would send e-mail but they wouldnt receive. I tried everything but could not get the test e-mails to receive they would only send. I tried uninstalling exchange completely to start over in case I had installed it incorrectly. I deleted all the mailboxes and mistakenly removed all exchange attributes from the administrator user name. So now im trying to install exchange once again and it doesnt let me install because it keeps telling me that I have to instll with a user name that has full exchange administrative rights to use exchange. Well I delegated the rights using the Exchange administrative delegation wizard and gave full exchange administrative rights acess to the administrator, I tried installing again and it is still telling me that I need to use a user with full exchange administrative rights and it only lets me install custom and not typical.. it also wont let me install forest prep or domain prep. Can anybody help me with this?? Pleaseeeeeeeeeee helpppppppppp!!!