computer ip address

I am having trouble logging on to a router. Netgear told me to check the comp. IP address. I am running XP and was wondering how to check it and if it is wrong how to change it.
Thanks
David

 

IP2 - determine your true IP address
"Primarily designed for users of "always on" Internet connections who use hardware NAT routers, IP2 is a small program that you can use to determine your true Internet accessible IP address. Unlike traditional IP utilities that only show your computer`s LAN IP, IP2 will show you what your IP address is from the perspective of an "outsider" on the Internet and is essential if you need to provide somebody with your true Internet IP address when your PC is working behind a router. Shows both WAN and LAN IPs, computer name and DNS name, all of which can be easily copied to the clipboard."

 

FYI

Start >Run> CMD than ipconfig /all this will show you your IP address and your MAC address