DHCP Client Service Procedure Not Found

Question

I have a W2008R2 Standard server (DC) holding both DHCP and DNS roles.  When the server was originally built the (migrated from 2003) DHCP did not load properly and per a Microsoft support incident we backed up the existing DHCP and rebuilt it. Everything
was working fine however the DHCP Client Service does not run.  This was back in 2012 so I don't recall if it the service was started and quit or if we just didn't notice that the Client Service was not running.  It has not been a problem for me
until now.  I need to run a new backup agent on this server and it requires the DHCP Client Service to be running.  I did notice upon a reboot that the service was "stopping" and will not restart.  It appears as though it does start
on boot and then immediately stops as I would not have caught the "stopping" status had I not went into the Services mmc right away.  The error that I get when trying to restart is 127:  The specified procedure could not be found.  This
is the only info logged in the event viewer as well.  The service is configured to start using Network Service credentials and is set to automatic.  The dependencies are:  "depends on" Ancillary Function Driver for Winsock & TCP/IP
Protocol Driver. The WinHTTP Web Proxy Auto-Discovery Service depends on the Client Service.  I have noticed on two other W2008R2 servers that the dependencies are different: The "depends on" are:  Ancillary Funtion Driver for Winsock,
NetIO Legacy TDI Support Driver and Network Store Interface Service. The components depending on the Client Service are the same on all servers.  I'm not sure if these differences are due to the fact that this server is running DHCP server and the others
are not? Or is this difference the reason for my issue?  I'm hesitant to change these parameters without some guidance for fear of trashing my entire box.  I did remove and completely rebuilld/reinstall the DHCP server role last night, hoping that
may fix the issue, but no luck.  I've run DNS tests & DCDiag with no issues found.  Anyone familiar with this problem?  What to do? Thanks!

Answer 1

Updates:  There are no events being reported at all in the DHCP Service log.  Things I have tried thus far:  
All Windows Updates installed
Uninstall and re-install the DHCP Server
Reset Winsock
Made sure permssions are set to Full for both Network Service & Local Service accounts (I tried changing the logon account to Local Service also).   
I noticed on another (working)  W2008R2 server that the dependencies were different although this server did not hold the role of DHCP Server.  The problematic server only listed Ancillary Function Driver for Winsock & Tcpip.  The working
server listed Ancillary Function Driver for Winsock, Network Store Interface Service and NetIO Legacy TDI Support Driver.  I then changed the dependencies to match that of the working server.  Verified that all of these were "started" in
Device Manager.  The DHCP Client Service now fails with Error 1079:  The account specified for this service is different from the account specified for other services running the same process.  (I did find a Microsoft Fixit for this--didn't
make any difference though).
I noticed on the other working server that the logon account for DHCP Client Service is actually LocalServiceNetworkRestricted.  I had set it to LocalService.  After making this change, my error now has changed to: Windows could not start the DHCP
Client service on Local Computer.  Error 1314:  A required privilege is not held by the client.
I split my DHCP scope and set up a second DHCP server to determine what effect the DHCP Server role had on things. I don't know that I've noticed anything to be honest.  So moving on...  
I mirrored the permissions in the registry to those of the new (additional) DHCP server for the following key:  HKLM\System\CurrentControlSet\Services\DHCP.  When I compare the permissions I notice that the problematic server is missing some
entries.  The working server has:  SYSTEM, LOCAL SERVICE, NETWORK SERVICE, Administrator, Users, Network Configuration Operators & Dhcp.  The troubled server does not list Network Configuration Operators or Dhcp.  I was able to add
the NW Configuration Operators ( a built-in security group), but do not see anything for Dhcp other than user groups for DHCP Admins & Users.  Based on what I see on the working server, I don't think that is the right thing to add.   
I also noticed that some keys were missing for this reg entry vs. the same key on the second server.  Missing were (all under the HKLM entry above):  RequiredPrivileges (REG_MULTI_SZ) value:  SeChangeNotifyPrivilege SeCreateGlobalPrivilege  ServiceDll
(REG_EXPAND_SZ) %SystemRoot%\system32\dhcpcore.dll (*I did verify this file does exist) and ServiceSidType (REG_DWORD) value:  1.  I added these reg keys. I also noticed that the troubled server has a subkey titled Enum.  There are 4 values
listed:  Default (REG_SZ), no value.  0 (REG_SZ) Data value= Root\LEGACY_DHCP\0000, Count (REG_DWORD) Value: 1 and NextInstance (REG_DWORD) Value: 1.  The working server does not have this key. 
In comparing the reg values on each server, the only significant difference that I've notice other than what is listed above is HKLM\System\CurrentControlSet\Services\Dhcp\Parameters.  On the working server the ServiceDll is dhcpcore.dll.  On the
server having the issue that value is defined as dhcpcsvc.dll.  I'm suspect that this could be a contributing factor, but have not made the change yet.
I am still sitting with the error 1314:  A required privilege is not held by the client.
So this is where I'm at...Any ideas would be appreciated as I'm really trying to avoid having to rebuild this entire server.  Thank you