I have a motorola surfboard sb5100 cable modem and it is connected to the PC by USB. It automatically configures everything using DHCP. When i connect the modem to the netrwork card (using a cat5e UTP cable) the modem can't configure itself by using the DHCP server. Windows says aquiring network addres for 2 minutes and then it just stops. What can the problem be.
I have another problem. If i restart the modem while my PC is running, the modem light start to light up but when the las one (online) light turns on the PC restarts (a fatal error happens). This happens sometimes whitout restarting the modem. Simply i turn on the PC and as soon as the WindowsXP welcome screen appears another fatal error and the PC restarts.
You dont have the ethernet and usb plugged in at the same time do you?
Try a different ethernet cable.
When going from usb to ethernet try unplugging the modem when the computer is off. Change the cable connections, plug the modem back in, once its done booting turn the computer on.
try that and see what happens.