Microsoft has released a new tool for IIS diagnostics called Trace Diagnostics. It’s a Diagnostics tool to assist in using Enterprise Tracing for Windows (ETW)
Service Pack 1 for Windows Server 2003 has very detailed diagnostics information built in. With Trace Diagnostics, you can effectively use these diagnostics built-in by monitoring the requests to an IIS web server in real-time, or, follow a request throughout the IIS processing pipeline to find failures.
Included in this download are three individual tools:
1). Request Viewer
2). IISREQMON.exe
3). IISTRACE.exe
Read more and download at source.