Active Directory issues with SBS 2008. Can't use any management tools or NTDSUTIL or make changes to DNS.

In July of 2010 I migrated a SBS2003 system to a SBS2008 system. There were a few hiccups along the way but eventually everything worked out fine and the original server was demoted and shut itself down.

Fast forward to now, June 2013, and now I'm seeing errors in the event log that read:

"This server is the owner of the following FSMO role, but does not consider it valid."

"This directory server has not recently received replication information from a number of directory servers."

And when running NTDSUTIL I cannot attach to the domain controller by either its name or the domain name. I constantly get the following error:
"DsBindWithSpnExW error 0x6ba(The RPC server is unavailable"

I have read and tried every conceivable solution I have been able to find. However, the difference between my situation and every other scenario that I have come across is that there is normally another domain controller available. This is not my case.

Here is my configuration:

1 - SBS 2008 server.

7 - Workstations running Windows 7 Professional

I cannot run Active Directory Users and Computers, Active Directory Domains and Trusts, or make any changes in the DNS. However DNS is working and my domain controller points to itself as the only domain controller and does resolve its name to the proper IP address.

What I have been able to track down is that the original domain controller did not properly demote and there is still a ton of references to it in Active Directory but I can't run any of the necessary tools to remove the reference and seize the roles.

Is there anyone out there who can help?

Thanks in advance for your suggestions