When you run the EXEC master..xp_cmdshell('SET USER') extended stored procedure, it returns the security context of the cluster service, NOT the SQL Server 2000 service account.

NOTE: When you run a CmdExecJob job step that has SET USER on a SQL Server 2000 cluster, it also returns the wrong context.

To workaround this behavior, download and use the Windows 2000 Resource Kit Tool: Whoami.exe.

The Whoami.exe command in a xp_cmdshell extended stored procedure returns the SQL Server 2000 service account.

NOTE: When you run a CmdExecJob job step that has Whoami.exe on a SQL Server 2000 cluster, it returns SQL Server Agent service context.