exchange 2000 installation in a lab

I have installed one server 2000 made it pdc by installing active directory and networked it to a 2000 proffisional in a lab. I was able to insatall sql 2000 0n the server but am unable to install exchange 2000. Once it reaches the component selection it does not give me the option to click next it gives me just back or cancel. Can you help ?

Thanks