Verify that there are no dependencies or extra resources other than those created by the SQL Server setup on any of the SQL Server cluster resources. Resources such as file
shares, print servers, etc.must always have a unique network name and an IP address resource. You must remove any such non-default dependencies before you install SQL Server 2000 SP4. No dependencies other than those supplied by the SQL Server setup should be used.
For example, if you have MSDTC resource in the SQL group and if MSDTC is
dependent on SQL Server Network Name and SQL IP Address then you may have
this issue. If this is the case then you will need to remove the dependencies and then try running the setup again.
If you still have the same problem, then the next step will be to review
the logs. I would start with the sqlsp.log (created on the node where you
ran the SP4 setup).
SQL Server 2000 Service Pack 3, Service Pack 3a, or Service Pack 4
pre-installation checklist for SQL Server 2000 virtual server for failover