If Phil's advice does not work you can try this. Assuming that you have either a cable or ADSL connection to the internet you may have either a static (never changes) or dynamic (may change) IP. If you have a static IP you will have to request the change through your ISP. If you have a dynamic IP you can try opening a DOS window and typing the following commands ipconfig /release (then hit enter) then type ipconfig/renew (then hit enter). Many times even a dynamic IP is semi-permanently associated with the physical address (MAC) of your computer's network card but it's worth a try.
Jrflex10er I'm not sure what you are trying to accomplish but anonymity on the Internet is not possible at this time so don't take any unnecessary risks. Using encrypted email and chat is a must if you are conducting sensitive business but your location and identity can easily be discovered in a number of ways no matter what you do. The only safe bet is using a public use PC such as those found at a university or library. Be safe bro.
This is the easiest way to get a new IP address if you get a randomly
assigned IP from your internet provider. Most people don't have static
IP's because they don't need one and there's an extra charge (I just
ordered one from Verizon because I work from home and they are charging
me an extra $40 a month for it). I used to get a new one every time I
restarted my computer.