The IP address needs to be on the same network as your computer.
Most use a class c subnet (255.255.255.0) the 3-255's indicate the network ID
if you have an ip address of 192.168.1.100, your network is 192.168.1.0
You also need to make sure it's a unique number, so if you have 192.168.1.100, make sure the printer is something like 192.168.1.200
phone, gotta run but that might help a bit...