Ah, you're right.. OpenThread apparently bridges that gap : "The handle returned by OpenThread can be used in any function that requires a handle to a thread, such as the wait functions, provided you requested the appropriate access rights. The handle is granted access to the thread object only to the extent it was specified in the dwDesiredAccess parameter". So my call sequence should be :- 
Thread32First
OpenThread
SetThreadPriority

[download]
Does this look better ? Now I still need to make Process32First work...

In reply to Re^14: how to change process & thread priority on Win32 ? by rbutcher
in thread how to change process & thread priority on Win32 ? by rbutcher

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