c/c++: suchfunktion erzeugt 100% prozessor-auslastung

RunCount = 0;
while (ProgramRunning)
{
   if (!PeekMessage( &msg,0,0,0,PM_REMOVE))
   {
      // Keine Nachricht in der Queue, ein paar Searches durchführen.
      if (++RunCount < RUN_COUNT_MAX)
      {
         SearchOnePart();
         continue;
      }
   }
   RunCount = 0;

   // Standard Windows-Nachrichtenschleife:
   while (GetMessage(&msg, NULL, 0, 0))
   {       
      TranslateMessage(&msg);
      DispatchMessage(&msg);
   }
}

// thread_test.cpp : Definiert den Einsprungpunkt für die Anwendung.
//

#include "stdafx.h"
#include "resource.h"
#include <stdio.h>
#include <windows.h>	//CreateThread()

#define RSTRING "thread running "

HINSTANCE hDlgInstance;
BOOL repeat = TRUE;		//globaler stopflag
BOOL running = FALSE;	//globaler runningflag

LRESULT CALLBACK About(HWND, UINT, WPARAM, LPARAM);

void initComponents(HWND);
DWORD CBIndex2Refresh(HWND);

void startThread(HWND);
unsigned long __stdcall checkRepeat(void*);
void endThread();

//////////////////////////////////////////////////////////////////////////////////////////
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
 	hDlgInstance = hInstance;
	DialogBox(hDlgInstance, (LPCTSTR)IDD_ABOUTBOX, NULL, (DLGPROC)About);
	
	return 0;
}

//////////////////////////////////////////////////////////////////////////////////////////
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	switch(message)
	{
		case WM_INITDIALOG:
			initComponents(hDlg);
			return TRUE;

		case WM_COMMAND:
			switch(LOWORD(wParam))
			{
				case IDOK:
				case IDCANCEL:
					if(running)
					{
						//stopflag setzen
						endThread();
						//warte bis wirklich die threadzeit abgelaufen ist
						Sleep( (CBIndex2Refresh(hDlg)+1) );
					}
					EndDialog(hDlg, LOWORD(wParam));
					return TRUE;
				break;

				case IDC_START:
				{
					//thread erzeugen und starten
					startThread(hDlg);
				}
				break;

				case IDC_END:
				{
					//thread beenden
					endThread();
				}
				break;
			}
	}
    return FALSE;
}

//////////////////////////////////////////////////////////////////////////////////////////
void initComponents(HWND hParent)
{
	//fenster-titel
	SetWindowText(hParent, "ThreadTest");

	//textfelder
	SetDlgItemText(hParent, IDC_STATUS, "current thread status");
	SetDlgItemText(hParent, IDC_DESCR, "refresh time:");

	//buttons
	SetDlgItemText(hParent, IDC_START, "start thread");
	SetDlgItemText(hParent, IDC_END, "end thread");
	SetDlgItemText(hParent, IDOK, "close");

	//combobox
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"0,1 sec");
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"0,3 sec");
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"0,5 sec");
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"1,0 sec");
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"1,5 sec");
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_ADDSTRING, 0, (LPARAM)"2,0 sec");
	//default: nach erzeugen, den 3ten markieren
	SendDlgItemMessage(hParent, IDC_REFRESH, CB_SETCURSEL, WPARAM(2), 0);

}

//////////////////////////////////////////////////////////////////////////////////////////
DWORD CBIndex2Refresh(HWND hParent)
{
	int cbIndex;

	cbIndex = SendDlgItemMessage(hParent, IDC_REFRESH, CB_GETCURSEL, 0, 0);
	switch(cbIndex)
	{
		case 0:
			return(100L);//millisekunden
		case 1:
			return(300L);
		default:
		case 2:
			return(500L);//default auswahl
		case 3:
			return(1000L);
		case 4:
			return(1500L);
		case 5:
			return(2000L);
	}
	return(NULL);
}

//////////////////////////////////////////////////////////////////////////////////////////
void startThread(HWND hParent)
{
	HANDLE hMyThread; 
    DWORD id;

	if(!running)
	{
		repeat = TRUE;
		hMyThread = CreateThread(NULL, 0, checkRepeat, hParent, 0, &id);
	}
}

//////////////////////////////////////////////////////////////////////////////////////////
unsigned long __stdcall checkRepeat(void *hParent)
{
	char out[18];
	char *points[6]={"",".","..","..."," ..","  ."};
	int pos = 0;

	running = TRUE;

	while(repeat)
	{
		

		Sleep(CBIndex2Refresh((HWND)hParent));
		sprintf(out, "%s%s", RSTRING, points[pos]);
		if(pos == 5)
			pos=0;
		else
			pos++;
		SetDlgItemText((HWND)hParent, IDC_STATUS, out);
	}	

	running = FALSE;
	SetDlgItemText((HWND)hParent, IDC_STATUS, "thread stopped");

	return(0);//dummy-ret
}

//////////////////////////////////////////////////////////////////////////////////////////
void endThread()
{
	repeat = FALSE;
}