Hire Windows Server expert to sort out DNS/AD problem & BPA errors

This project is to resolve Windows BPA errors and solve a DNS/AD problem. PROBLEM: We have a problem where new computers on the network cannot login to the server domain (cannot resolve the hostname). BACKGROUND: We migrated a Windows Server 2003 server to Windows Server 2012 R2 Essentials 1 year and a half ago. There may be some sort of issue with the 2003 server not being completely removed. There should only be 1 server in the forest now, that runs both Active Directory and DNS, but for some reason the DNS says the Active Directory isn't initialised but it is. Tried reinstalling DNS Controller, no change in the problem. After running BPA we have the following errors: - The AD DS BPA should be able to collect data about the DNS record ... from the DNS servers ... from the Domain Controller - The DNS server [login to view URL] mst be able to resolve names in the forest root domain name zone Event ID: 4013 The description for Event ID ( 4013 ) in Source ( Microsoft-Windows-DNS-Server-Service ) cannot be found. Either the component that raises this event is not installed on your local computer, or the installation is corrupted. You can install or repair the component on the local computer, or contact the component manufacturer for a newer version. If the event was saved from another computer or forwarded from a remote computer, you might have to include display information with the events when saving them or when setting up the forwarding s . DNS Error: The DNS server is waiting for Active Directory Domain Services (AD DS) to signal that the initial synchronization of the directory has been completed. The DNS server service cannot start until the initial synchronization is complete because critical DNS data might not yet be replicated onto this domain controller. If events in the AD DS event log indicate that there is a problem with DNS name resolution, consider adding the IP address of another DNS server for this domain to the DNS server list in the Internet Protocol properties of this computer. This event will be logged every two minutes until AD DS has signaled that the initial synchronization has successfully completed. I have made a mirror of the drive and placed it into another machine (on a different network) for troubleshooting purposes. After the problem is resolved I will need exact steps to be provided with screenshots in order to fix the problem on the live machine (or we will provide access to the live machine to apply the fix).