Proxy Server 2.0 Opening Ports

I need to open a couple ports on my server for secure transactions.

How do I see what ports are open and how to open the ports needed that are not open now ?

Basically I need ports:
80
443
7143
7001

Any help would be appreciated. Win NT4.0 Service Pack 5, Proxy Server 2.0, Exchange Server 5.5.

Thanks,
Mark Jervis