WPT is a deep troubleshooting toolkit used to triage many scenarios in the Windows ecosystem. We can use it to troubleshoot power consumption problems, high CPU usage scenarios, heap leak analysis, and many other scenarios. This toolkit is covered in Clint Huffman's Windows Performance Analysis Field Guide, so I will not delve deeper into it here. Suffice it to say, the toolkit has a steep learning curve and requires a good knowledge of the Windows kernel and system architecture.
Michael Milirud gave a talk in 2011 in California on this subject and is on Channel 9 at http://channel9.msdn.com/events/BUILD/BUILD2011/HW-59T .