Scenario, I have to machines M1 and M2, in which M1 is domain controller, running windows 2k server, maintaning ACTIVE Directory, it has also configured ISA Server(to provide internet access to the users), the thing is that M1 provides two services, right now, 1. Users Authentication (PDC) 2. Internet Access (thru ISA) ------------- I want to do this thing.... I want M1 to serve as PDC only, and distribute "Internet Access" task to M2, so that work load can be balenced, ----------- but thing that must be kept in mind that , i want to import the users of M1(maintained by Active Directory) to M2, so that i dont have to recreate the users of M1 to machine M2

First off, there is no "PDC" in a 2000 Active Directory domain. A server is either a DC (domain controller) or it's not. If you promoted M2 to a DC, replication would take care of the users and you could still use it to host internet for the clients just by setting up RRAS/NAT on it.