SQL 2000 SP4 on a cluster

If I have SQL Server 2000 ENT edition on a cluster active/passive. Do I need to apply the service pack on the active instance, and then bring up other instance and reapply? While I am at it, I believe I still have to apply the hotfix for the awe memory problem also?

No, just apply on active node and it'll take care of passive one. But I always failover sql to passive node to double check version number after applying sp.

Will do thanks

If you use AWE memory then you need to apply the hot fix.