No Windows Server 2003 (IIS 6) existe a propriedade Metabase AspErrorsToNTLog (boolean).
Consulte este artigo da Microsoft TechNet: Propriedade Metabase AspErrorsToNTLog (IIS 6.0) .
The AspErrorsToNTLog property specifies which ASP errors are written to the Windows event Log. ASP errors are written to the client browser and to the IIS log files by default. AspErrorsToNTLog is set to FALSE by default, and modifies the AspLogErrorRequests property in the following way: - If AspLogErrorRequests is set to FALSE, then ASP errors are not written to the Windows event log, regardless of the value of AspErrorsToNTLog.
If AspLogErrorRequests is set to TRUE, then if IIS fails to write an item to the IIS log file, the item is written to the Windows event log as a warning, regardless of the value of AspErrorsToNTLog.
If AspLogErrorRequests is set to TRUE and AspErrorsToNTLog is set to FALSE, then only the most serious ASP errors are sent to the Windows event log. Serious ASP errors are numbers 100, 101, 102, 103, 104, 105, 106, 107, 115, 190, 191, 192, 193, 194, 240, 241, and 242.
If AspLogErrorRequests is set to TRUE and AspErrorsToNTLog is set to TRUE, then all ASP errors are written to the Windows event log. Note This property does not control logging requests to the IIS log files. To accomplish this see the LogType and DontLog properties. Also, this property does not control IIS Event Messages, which are always sent to the Windows event log. This property is a process-level property. If this property set at the Web service level, it is applicable to all in-process application keys. Metabase property settings at the Web site level or lower are ignored for in-process applications unless the Web site key is isolated as an out-of-process application.
Este artigo explica como você pode alterar o arquivo de metabase do IIS no IIS 6: Modificar a Metabase do IIS diretamente (IIS 6.0)