What is SQLDiag?

In SQL Server 2005, the SQLdiag utility is a general purpose diagnostics collection utility that can be run as a console application or as a service. For more information about sqldiag, please refer to SQL Server books online documentation: http://msdn2.microsoft.com/en-us/library/ms162833.aspx.
Thought default templates are available, shipped products don't have a configuration user interface that would allow you to customize what profiler trace events or perfmon counters to collect. If you want to customize data collection, please use pssdiag/sqldiag manager from codeplex.