Because Windows 2000 (Win2K) no longer supports the directory replication service, you must develop an alternative method to replicate logon scripts among Win2K domain controllers. Microsoft uses the automated File Replication Service (FRS), which is a key Dfs component, to synchronize file directories across servers on a Win2K network. (For more information about Dfs, see "Dfs in Windows 2000," Winter 1999/2000.)
During installation, Win2K automatically configures FRS to replicate the shared system volume (SYSVOL) directory (stored in \%systemroot%\sysvol by default) among all domain controllers on your network. You can therefore put your logon scripts within the SYSVOL directory structure to replicate them throughout your Win2K network.
However, if you configured your PDC as the export server for your logon scripts and your BDCs act as import servers (a very common configuration), you might experience a problem if you migrate your PDC first. You'll effectively disable the replication of logon scripts throughout your entire configuration if you upgrade the export server first. Therefore, Microsoft recommends designating another server as the export server on your network and upgrading that system to Win2K after you've migrated all other systems.