The wizard detected an existing computer account in Active Directory Domain Services (AD DS) for a read-only domain controller ...

The wizard detected an existing computer account in Active Directory Domain Services (AD DS) for a read-only domain controller that matches the name of this computer. If you install AD DS on this computer, this computer will become a read-only domain controller and will use the existing computer account. If you do not want to make this computer a read-only domain controller, you must rename and restart this computer before you install AD DS.

Do you want to continue and make this a read-only domain controller using the existing account in AD DS?