ip address help!

Hiya,
I have a problem. Bear with me because I don't know a lot about computers! Basically we have set up broadband internet in my flat (without a phone line) and my flatmate's laptop is connected to the router via a USB LAN wireless stick, which works fine. The second computer in the flat (my computer), is connected with a wireless card. However the hard drive was recently replaced, and the computer has no IP address. I have been told I need to assign a new IP address to teh computer, but have no idea how to do this! It is somehow connected to the router, and is sending signal (activity packets) to the receiver but not receiving them back. It says it is connected to the wireless network and signal strength is good to excellent.

At first, the IP and Subnet addresses were set to 00.00.00, but i clicked repair the connection, and it came up with an IP and Subnet address but said that the IP address could not be renewed and to contact the Network Administrator or ISP. I cannot do this because we are currently studying in Spain, so anyone who comes to look at the computer has difficulty because the system is in English.

Any help would be greatly appreciated!!!

many thanks, nikki