When you boot the 1st domain controller within the environment which has more than 1 DC, by default the DC is waiting for initial inbound replication from the other DC. But because this is the first DC you boot, this is going to take a while
To avoid this, add the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters
Value name: Repl Perform Initial Synchronizations
Value type: REG_DWORD
Value data: 0
Add Reboot!
Do not use this method in the producation environment
