HANDLE         hProcessSnap = NULL; 
    BOOL           bRet      = FALSE; 
    THREADENTRY32  te32      = {0}; 
     
    //  Take a snapshot of all processes in the system. 

    hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0); 

    if (hProcessSnap == INVALID_HANDLE_VALUE) 
        return (FALSE); 
     
    //  Fill in the size of the structure before using it. 
    te32.dwSize = sizeof(THREADENTRY32); 

    // Get first process information
    Thread32First(hProcessSnap, &te32)

    // get the thread priority
    HANDLE hThread;
    hThread = OpenThread(THREAD_SET_INFORMATION|THREAD_QUERY_INFORMATION, FALSE, te32.th32ThreadID); 

    // set new priority class
    if (SetThreadPriority(hThread, threadPriority) != TRUE)
    {
    	cerr << "SetThreadPriority() ";
    	printError();
    }
    CloseHandle(hThread);