Sometimes if you replace a server or even migrating you will encounter the error:
the specified servers are already present in the directory service
The error exactly says what it means, the DHCP server you are trying to authorize already exist within the Active Directory domain.
This is how you fix it!
- Start Active Directory Sites and Services
- Right-click on the Active Directory Sites and Services (myserver.mydomain.com) node > View > Show Services Node
- Go to node Services > NetServices
- You will find your DHCP servers here, delete the one you are trying to Authorize
- Now try to authorize your DHCP server again, it should now work!