Ensure that your NIC is properly configured (IP address, subnet mask, default gateway, etc.), then try pinging the PDC by name. If you can't ping the PDC by name, try pinging by IP address. If that is unsuccessful, try pinging the server's own address. If you can do this, you have a connectivity issue. If you can't ping the server itself, try re-installing the NIC driver and/or the IP stack.
Before you can join the domain you must be able to communicate with it. Once you have solved the communication issue, you should be able to join the domain (without re-installing the OS).