Windows XP "No response DHCP Server" message?

Hi, I bought a refurbished laptop with Windows XP OS on it. I can get it to hook up wirelessly to someone's unsecured wireless signal, but I can't get it to hook up to my wireless Comcast signal. My Comcast signal is fine (my spouse's computer is working fine on the wireless signal). I keep getting a message that says "No response DHCP server". Can you help me? The wireless internet thing I have on my computer is an "Intel" device of some kind. Thanks very much, I'm no techie, so please don't explain it in complicated jargon.