I rleased/renewed my IP Address. But after I renew it, it comes back as the Same address!! CAn someone help?? Also why can one computer on my network post thigs (online forms, craigslist etc,) but this one can't?? It does like one out of every 100 times? PLEASE HELP!!

What is wrong with the Same address? If it is available, your computer can still use it. There is no problem with that. Your DHCP server keeps track of the addresses used and will supply the same address when your computer requests a renewal.

What type of network do you have? Is it a home network or business network? Are you in control of the Internet access and filtering or is someone else?

Is the computer set to Obtain the IP automatically or is it a static IP ( one that you have set ) What type of router are you using? What type of Internet Connection do you have?

Another question is do you have a IP address tied to a MAC address of your WAN card. You can define this in your router that every time this MAC address connects , one it can connect and 2 use this address. There are many reason why one computer could post things and another not. Do you have a personal firewall on each of the computers and certain ports are needed open in order to allow craigs list or other options. Another option is that you have created a DMZ with your router and are forwarding certain types of outside requests coming in only to one computer. This again is done in the router