No, we cannot have two primary DNS zones. Why because if u have two primary DNS zones some clients contacts FIRST one, some clients contacts second one ACCORDING to their configuration in TCP/IP properties. Then you will get problems. Actually Primary DNS ZONE means Single master. i.e., master is only one that is only one primary DNS zone. But you can have as many as SECONDARY zones.

To overcome from above problem (i.e., single master problem) in Windows 2000 we have ACTIVE Directory Integrated zones, which are multi masters.

No, we cannot have two primary DNS zones. Why because if u have two primary DNS zones some clients contacts first one, some clients contacts second one according to their configuration in TCP/IP properties. Then you will get problems. Actually Primary DNS zone means Single master. i.e., master is only one that is only one primary DNS zone. But you can have as many as Secondary zones.

To overcome from above problem (i.e., single master problem) in Windows 2000 we have Active Directory Integrated zones, which are multi masters.