Why won't DHCP Client Service start?

W2008 R2 Domain Controller hosting DNS and DHCP. The DHCP Client Service will not start with error 127: The specified procedure could not be found. Event viewer renders same message. SHOULD this service be running on a DC that is also the DHCP server? I read that the DHCP Client Service send dynamic updates to DNS so I have not set DNS scavenging for the time being. What risk is there if I leave scavenging off although best practice is to have it configured. Cannot find any articles indicating how to correct this. This server has only been up for a month so I'm not sure when this service quit or if it was ever running. Any ideas? Thank you.