true, so if it gets an I.P. the driver must be good.
Are you sure there is only one DCHP Server on the network? There isnt another conflicting DCHP server set up on a Router or WAP etc which has the DNS missing so that the inital IP assigned isn't from the true DCHP Server?
Does it work ok if you assign a static IP and DNS server or does it still require a renew?
well, set it a static address on the lan and see if it holds after a reboot. If it does, forget about it and leave it static lol. You never know it may sort itself out later in time with a windows update for either w7 or the driver...
What happens when you unplug the Cat 5 cable and plug it back in? I was having a similar problem with my Marvell Yukon NIC. Sometimes I would get a not connected error but others just a DNS error with local connectivity only. If I unplugged and reconnected most of the time it would fix itself. However, I noticed I had literally thousands of driver errors in the event viewer (26,000+ in 24 hours). I installed the latest NIC drivers from the Marvell web site and the problems all went away.