How to reduce CPU Usage in VC++?

void gdiscreen()
{
	using namespace Gdiplus;
	GdiplusStartupInput gdiplusStartupInput;
	ULONG_PTR gdiplusToken;
	GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
	int c=0;
	HDC scrdc, memdc;
	HBITMAP membit;
	HBITMAP hOldBitmap;
	CString lpfilename;
	char buffer[1000];	   
	
	for(;;)
	{		
		scrdc = ::GetDC(0);
		int Height = GetSystemMetrics(SM_CYSCREEN);
		int Width = GetSystemMetrics(SM_CXSCREEN);
		memdc = CreateCompatibleDC(scrdc);
		membit = CreateCompatibleBitmap(scrdc, Width, Height);
		hOldBitmap=(HBITMAP) SelectObject(memdc, membit);
		BitBlt(memdc, 0, 0, Width, Height, scrdc, 0, 0, SRCCOPY);
		//Gdiplus::Bitmap bitmap(membit, NULL);
		Gdiplus::Bitmap* bitmap =  ::new Bitmap(membit, NULL );

		CLSID clsid;
		GetEncoderClsid(L"image/jpeg", &clsid);
		sprintf_s(buffer,"C:\\Program Files\\image%u.jpeg",c);		
		lpfilename=buffer;				
		bitmap->Save(lpfilename, &clsid); 
		IStream* tmpbuf = NULL;
		CreateStreamOnHGlobal(NULL, true, &tmpbuf);
		bitmap->Save(tmpbuf, &clsid);
		HGLOBAL hg = NULL;
		HRESULT  hr = GetHGlobalFromStream(tmpbuf, &hg);
		SIZE_T uSize = GlobalSize(hg);
		//GlobalUnlock(hg);
		

		int len=(int)uSize;  
		CFile file;
		BYTE buf[150];
		CStringA charstr(lpfilename);
		CString strblob;
	   const char *szSingle;
       szSingle=((const char *) charstr);	

		CString strDateTime;
	   SYSTEMTIME datetimenew;
			::GetLocalTime(&datetimenew);
			strDateTime.Format(_T("%02i-%02i-%02i %d:%d:%d"),
								datetimenew.wYear,
								datetimenew.wMonth,     
								datetimenew.wDay,       
								datetimenew.wHour,
								datetimenew.wMinute,
								datetimenew.wSecond);
		
		CdbImages       dbImages(&theApp.m_DB);

		dbImages.Open();
        dbImages.AddNew();

        CFile		fileImage;
        CFileStatus	fileStatus;

        fileImage.Open(lpfilename, CFile::modeRead);
        fileImage.GetStatus(fileStatus);

		dbImages.m_dateTime = strDateTime;
        //dbImages.m_BLOBName = fileImage.GetFileTitle();		
		dbImages.m_BLOBName = SqlStr3;
		
        dbImages.m_BLOBImage.m_dwDataLength = fileStatus.m_size;

        HGLOBAL hGlobal		= GlobalAlloc(GPTR,fileStatus.m_size);
        dbImages.m_BLOBImage.m_hData = GlobalLock(hGlobal);
		
        fileImage.Read(dbImages.m_BLOBImage.m_hData,fileStatus.m_size);
		dbImages.SetFieldDirty(&dbImages.m_BLOBImage);
        dbImages.SetFieldNull(&dbImages.m_BLOBImage,FALSE);
		dbImages.m_log_user = loguser;
        dbImages.Update();
		fileImage.Close();		
		 dbImages.Close();
		 GlobalUnlock(hGlobal);
		
		::delete bitmap;
		bitmap = NULL;
		DeleteObject(memdc);
		DeleteObject(membit);
		::ReleaseDC(0,scrdc);
		CFile::Remove(lpfilename);    		
			
		
		 //Sleep(10000);			 
		 int iSecret, iRandom;  
		 iSecret = rand() % 20 + 1;
		iRandom=iSecret*60000;
		Sleep(iRandom);
	    c++;	    
		}		
		
		GdiplusShutdown(gdiplusToken); 
}

int GetEncoderClsid(const WCHAR* format, CLSID* pClsid)
{
	using namespace Gdiplus;
	UINT  num = 0;          // number of image encoders
	UINT  size = 0;         // size of the image encoder array in bytes

	ImageCodecInfo* pImageCodecInfo = NULL;
	GetImageEncodersSize(&num, &size);
	if(size == 0)
		return -1;  // Failure

	pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
	if(pImageCodecInfo == NULL)
		return -1;  // Failure

	GetImageEncoders(num, size, pImageCodecInfo);

	for(UINT j = 0; j < num; ++j)
	{
		if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 )
		{
			*pClsid = pImageCodecInfo[j].Clsid;
			free(pImageCodecInfo);
			return j;  // Success
		}    
	}

	free(pImageCodecInfo);
	return 0;
}