The IP address of your computer can be set from the command prompt by running the following commands at an administrative level prompt:
Code:
netsh interface ip set address name="Local Area Connection" static 123.123.123.123 255.255.255.0 123.123.123.1 1
Local Area Connection is the name of the adapter you want to modify. In single NIC systems it is normally called Local Area Connection.
Code:
123.123.123.123 is the IP address you want to set.

255.255.255.0 is the subnet mask.

123.123.123.1 is the gateway.
1 is the gateway metric. You can leave this as 1 for almost all cases.

If you want to enable DHCP you can run:
Code:
netsh interface ip set address name="Local Area Connection" dhcp
There are two commands for DNS since administrators typically configure a primary and secondary DNS server.

For the primary DNS run:
Code:
netsh interface ip set dns name="Local Area Connection" static 208.67.222.222
For the secondary run:
Code:
netsh interface ip add dns name="Local Area Connection" 208.67.220.220 index=2
If you want to configure the computer to use DNS from DHCP run:
Code:
netsh interface ip set dnsservers name="Local Area Connection" source=dhcp
When you are finished with all of your IP and DNS changes run ipconfig -all to review the new settings.