I posted this in wrong forum before..sorry.
Using ISP Comcast, windows xp sp3, I followed the following steps.
Start-run-CMD-txt box-ipconfig-ipconfig/release
IP goes to 00.000; then type ipconfig/renew...I get my original IP.
Can anyone help?
Thank you, Jim

and unless you have dynamic ip from comcast it won't change .
a quote from the site in the lower link .
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When someone manually configures a computer to use the same IP address each time it powers up, this is known as a Static IP address. In contrast, in situations when the computer's IP address is assigned automatically, it is known as a Dynamic IP address.
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http://en.wikipedia.org/wiki/IP_address

What IP is it giving you? I don't think your computer is able to release/renew your external IP address using command prompt, that must be done by your routers control page.

PS. Comcast IPs are dynamic, static is only default with business packages and I'm not even sure if you can add it on to a residential package.

you are correct ,but i think my provider will for me if im willing to pay the extra money ,but i could be wrong .

I was speaking specifically about comcast. It's true for MOST cable providers* based on the nature of the service, but I can only speak certainly about Comcast.

*many DSL services have static IPs no by default