Strange problem

We recently upgraded our domain from SBS 2000 to Windows 2003 Domain. Everything working except one Database server(OS:Windows 2000 Advanced) could not join domain. So we rejoined the Domain. Problem is I can’t see Local Area connections in network properties. It doesn’t display anything. Even in device manager if the select NIC and goto properties nothing happens. But when I tried to close Device Manager its ask me to close open windows that I can’t see. In taskmanager nothing shows. I need to configure network card with previous stastic IP address. Is there a command line to config. What is wrong?. Is there a DLL issue. please let me know. Is there any tool to fix this problem.
Thanks