On Windows 2003 Server, you may face an issue with the “DHCP Client” service. It keep failing at startup, causing a lot of troubles and instability of system services.
If you (and probably did) follow the Microsoft TechNet article # 895149 (http://support.microsoft.com/kb/895149 and it didn’t work for you, then you may try the following:
The article mentioned both (DHCP) and (TCPIP) subkeys, while didn’t mention the (Parameters) subkey under (DHCP). You’ve should set the same permissions for “Network Service” on the (Parameters) subkey as well. Then try to start up the service.
Good luck