Solution: Identify the computer holding the fsmo roles by using the command netdom query fsmo.
C:\Program Files\Support Tools>netdom query fsmo
Schema owner es-dc-01.magwinya.lan
Domain role owner es-dc-01.magwinya.lan
PDC role es-dc-01.magwinya.lan
RID pool manager es-dc-01.magwinya.lan
Infrastructure owner es-dc-02.magwinya.lan
The command completed successfully.