The system cannot log you on due to the following error. RPC Server is Unavailable.

Error : 
The system cannot log you on due to the following error :
RPC Server is Unavailable

Please try again or consult your system administrator.










Observations :
OS : Windows Server 2003, 64 Bit.
Domain Group policies are not getting applied.
Sometimes, domain is not pingable.
Event log gives following errors :



Solution : 

This is just workaround which I found in the Microsoft forum :
https://social.technet.microsoft.com/Forums/windowsserver/en-US/2e675354-62fc-4b09-874d-e97ca71c09c1/the-rpc-server-is-unavailable-while-trying-to-take-remote-desktop-of-2003-server?forum=winservergen&prof=required

Steps :
1) Logon to server using Local Administrator Account. (If you dont have it, create it remotely from another computer via Computer Management Console
2) Open Registry Editor. Start-Run-Regedit (Enter)
3) Navigate to following location :
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server
 
4) Create new DWORD Value - "IgnoreRegUserConfigErrors" and set its value to "1"




5) Its done. Now you will be able to login to Server using domain login.

6) Investigation on the Group Policy error is still going on. I will update this post once I get the solution.

Thank You.