In this episode of Defrag Tools, Andrew Richards, Chad Beeder and Larry Larsen continue looking at the Debugging Tools for Windows (in particular WinDbg). WinDbg is a debugger that supports user mode debugging of a process, or kernel mode debugging of a computer. This installment goes over the commands used to diagnose a Critical Section hang in a user mode application. We start with an overview of the four synchronization primitives and then delve deep in to temporary hangs, orphaned Critical Sections and deadlocks. We use these commands: ~*k ~*kv ~ ~~[TID]s !cs !cs <pointer> !locks Make sure you watch Defrag Tools Episode #1 and Defrag Tools Episode #23 for instructions on how to get the Debugging Tools for Windows and how to set the required environment variables for symbols and source code resolution.