computer on network not picking up internet
k, we are using attbi cable internet. we have four ip's that we are paying for. one of those ip's werent being used for a quite some time execpt when i had my friends over and i would let him use it. just recently(yesterday) and i had all of the ip's in use. as some of you know, attbi uses DHCP which makes it so the ip's sit in a pool like thing and when a computer needs an ip it assings it to the computer and we have 4 in our "pool". after a while when its not in use it puts it back in the pool until it gets used again. anyways, my moms computer that wasnt working when i had my lan party has internet again. so thats good. but we just put winxp on my brothers and sisters computer and tried putting them online but it wont get on. the lan works fine, its just that we cant get them online. and another wierd thing is, with xp, all you need to do is plug in the cable to the lan card and internet instantly works. thats how it was with 2 of my friends at the lan party. but it wont see it on my siblings computer. any ideas?