I had problems with ftp also when i first started getting into the scene, and thats one reason why i ended up here. click "Start" then click "run" then type "cmd" then hit enter. in the command prompt window that just popped up type "ipconfig" and hit enter, you should see somthing like this
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
E:\Documents and Settings\Administrator>ipconfig
Windows IP Configuration
Ethernet adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Ethernet adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
IP Address. . . . . . . . . . . . : 192.168.1.5
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
all you have to worry about is the IP Address. you will need to change your xbox's ip to almost match your pc's ip. for instance, my pc's ip is 192.168.1.5 so i should make my xbox ip like 192.168.1.6 or so on just changeing the last # of the ip.