What's my IP?
This article will explain to you how to find what IP address has been
assigned to you by your Internet service provider or the address that you
use on your LAN.
Windows 9x
For Windows 9x go to Start ->Run. In the 'Open' box type
"winipcfg" and click OK. This is a program that will give you
information about the network adapters you currently have in your
system. You should see a box appear that looks like this:

If you are connected to your ISP by a modem, make sure the
drop down box is on PPP Adapter like above. In the 'IP Address' box
where it reads 0.0.0.0 is your IP address that your Internet Service
Provider has assigned to you. In the 'Adapter' drop down box you can
change the adapter and if will give you its' respective information.
Windows NT
For Windows NT go to Start ->Run. In the 'Open' box type
'command' and click OK. This will give you a command prompt window.
At the prompt type "ipconfig/all" and press enter.
This will list information about all of the network adapters currently
in attached to your system. If you are looking for the IP address
that your Internet Service Provider has assigned you through your dial up
modem account, look for a heading that reads "PPP Adapter".
In the list under that heading there will be a IP Address, and that is the
IP address that has been assigned to you.