I guess first things first, check the leds on the front of the cable modem...You should have three solid lights, unless you have something other than a ericsson, toshiba, or motorola modem...If you do, go ahead and unplug your modem, plug it back in after a few seconds, and make sure that all three lights come on solid again...Once that happens go to winipcfg (I'm assuming you're using 9x), release the ip address and renew it...If that doesn't work check to make sure your NIC is installed properly and isn't sharing any resources with something like your video card or anything that might hog an irq...After that try removing and reinstalling TCP/IP...Make sure it is active by pinging 127.0.0.1...

Most cable services do use DHCP for IP allocation...And most of their tech support does suck...

If none of this works the best thing I can guess is A) Your account hasn't been properly activated on the cable provider's equipment B) You have a bad NIC or C) You have a bad cable. Or possibly a bad cable modem...

Caskethopper