While working with Microsoft on a SQL bug I have used a powerful tool (Process monitor) to troubleshoot the problem.
What is interesting with this tool:
* Simple, installation not required
* Filter is great: Filter can be applied on specific process or user or session etc
* UI is simple and efficient to clear old messages and no performance issues
* Exclude specific processes from UI to focus on what we need with just 2 clicks
* One click filter options to include/exclude specific processes (Network activity/ File System Activity/ Registry activity etc)
This tool can be downloaded from http://www.sysinternals.com -> Process Utilities -> Process Monitor