vista and xp cant connect at teh same time

> i have a small home network and i have two xp machines and my roomate just
> got a vista machine. we cant be connected to the internet through the network
> at the same time. if i was gone during the day and had both my machines off
> and he was home and had his on he would be on the network and using the
> connection. once i get home and i turn on my machines i have a limited/no
> connectivity on both of my xp machines. i have to rest the hub and cable
> modem several times to have my machines work and in that process my room
> mate's vista machine will no longer connect to the internet but it on the
> network (connection:local only) i dont know much about networking but i have
> tryed doing a few solutions i found on the net. such as setting the xp
> machine to a static ip. turning on an off the the dhcp. and reset the
> sinsock. i am running out of ideas. i cant find any firmware updates for my
> router. its some no name brand. i dont knwn, maybe buy a new hub?

> i have a small home network and i have two xp machines and my roomate just
> got a vista machine. we cant be connected to the internet through the network
> at the same time. if i was gone during the day and had both my machines off
> and he was home and had his on he would be on the network and using the
> connection. once i get home and i turn on my machines i have a limited/no
> connectivity on both of my xp machines. i have to rest the hub and cable
> modem several times to have my machines work and in that process my room
> mate's vista machine will no longer connect to the internet but it on the
> network (connection:local only) i dont know much about networking but i have
> tryed doing a few solutions i found on the net. such as setting the xp
> machine to a static ip. turning on an off the the dhcp. and reset the
> sinsock. i am running out of ideas. i cant find any firmware updates for my
> router. its some no name brand. i dont knwn, maybe buy a new hub?