New Exchange 2000 server not in site

I just installed a new Exchange 2000 server within our company. We have an exisiting 5.5 server at another location that this will be replacing. None of the services will start. I tried installing the SP3 for Ex 2000 and it will not let me. It keeps giving me an error about not finding the domain and not being in the site. How do I fix this and get this thing up and running? Thanks!