Dhcp client not getting IP address

I have a user whose machine all of a sudden, cannot accept an IP address from the Dhcp server. I was setting her up for connection to the Internet and just installed IE 5.0. The system needed to reboot and from then on she was not able to log back onto the LAN. I changed the network card...still nothing. I keep getting a service has failed at the login prompt and when I check the event viewer I would find the following events;
Event ID 7023. Event Id 1006, and Event Id 1003. Basically its saying that the dhcp client service cannot start, but it does not give a reason why. I put in a static address and the user is able to login now but I would really like to get the dhcp situation resolved. Any suggestions?