OK. lets go right back to basics.
1. please confirm IP address is set on NIC and server can ping itself
2. please confirm windows firewall is disabled
3. I think the DHCP error is a red herring - ignore it for now
4. Network cards do fail. Does the server have another NIC in it already that you can make active? if not can you buy one? - make sure you take the IP settings off the old NIC first
5. have you swapped the LAN cable and plugged into new port on the switch?
That will do for now
