Can someone help me with routing and remote access?

In Windows 2000 Server, it has routing and remote access service. Now our Server has such a problem: in routing and remote access console, I cannot view or modify its property.
Today I changed a new network interface card for external Internet connection; then other computers cannot have Internet access through NAT. In the meantime, I cannot view or modify the routing and remote access property.
Can someone help me with an easy solution, or do I have to reinstall the system?