Thread Wait Reason is only applicable when the thread is in the Wait state (see Thread State). It is 0 or 7 when the thread ...

Thread Wait Reason is only applicable when the thread is in the Wait state (see Thread State).  It is 0 or 7 when the thread is waiting for the Executive, 1 or 8 for a Free Page, 2 or 9 for a Page In, 3 or 10 for a Pool Allocation, 4 or 11 for an Execution Delay, 5 or 12 for a Suspended condition, 6 or 13 for a User Request, 14 for an Event Pair High, 15 for an Event Pair Low, 16 for an LPC Receive, 17 for an LPC Reply, 18 for Virtual Memory, 19 for a Page Out; 20 and higher are not assigned at the time of this writing.  Event Pairs are used to communicate with protected subsystems (see Context Switches).