inaccurate sleep

    while(Run)
    {

        FILETIME GameDllLastWrite = Win32GetFileTime(DLLSourcePath);
        if (CompareFileTime(&GameDllWriteTime, &GameDllLastWrite))
        {

            Win32UnloadCode(&Win32Code, DLLCopyPath);
            BOOL CopyResult = CopyFile(DLLSourcePath, DLLCopyPath, FALSE);
            if(!CopyResult)
            {

                Win32Code = Win32LoadCode(DLLCopyPath); // we got here after we unloaded the library yet we failed to copy to allow loading the new library
                goto EndCompareTime;
            }

            Win32Code = Win32LoadCode(DLLCopyPath);
            GameDllWriteTime = GameDllLastWrite;

            EndCompareTime:
            (void)0;
        }

        MSG Msg;
        while (PeekMessageA(&Msg, WindowHandle, 0, 0, PM_REMOVE))
        {
            UINT Message = Msg.message;
            switch (Message)
            {
            case WM_KEYUP:
            case WM_KEYDOWN:
            case WM_SYSKEYDOWN:
            case WM_SYSKEYUP:
                {
                    ProcessKeyboard(Message, Msg.wParam, Msg.lParam, &GameState);
                } break;

            case WM_SIZE:
                {
                    ProcessResize(WindowHandle, &BitMapInfo, &Win32Code, &GameState);
                } break;
            }

            TranslateMessage(&Msg);
            DispatchMessage(&Msg);

        }

        Win32Code.GameUpdate(&GameState);
        Win32PresentBitMapToScreen(WindowHandle, DeviceContext, &BitMapInfo, GameState.BackBuffer);

        QueryPerformanceCounter(&EndingTime);
        u64 ElapsedMicroSeconds = EndingTime.QuadPart - StartingTime.QuadPart;

        ElapsedMicroSeconds *= 1000000;
        ElapsedMicroSeconds /= Frequency.QuadPart;


#if SLEEP_ON
        u64 FrameTimeInMicroSeconds = 16000;
        u64 SleepTime = FrameTimeInMicroSeconds - ElapsedMicroSeconds;  // this might wrap if we sleep for too long
        if (SleepTime > 0 && SleepTime < FrameTimeInMicroSeconds)
        {

            Sleep((DWORD)SleepTime/1000);

        }
#endif
        QueryPerformanceCounter(&EndingTime);
        u64 ElapsedMicrosecondsAfterSleep = EndingTime.QuadPart - StartingTime.QuadPart;
        ElapsedMicrosecondsAfterSleep *= 1000000;
        ElapsedMicrosecondsAfterSleep /= Frequency.QuadPart;

        StartingTime = EndingTime; // reset our starting time
#if DEBUG_PRINT_MS
        char Buffer[1024];
        wsprintf(Buffer, "Elapsed Microseconds = %d \t| AfterSleep =%d \t| SleepTime = %d\n", ElapsedMicroSeconds, (s32)ElapsedMicrosecondsAfterSleep, (s32)SleepTime);
        OutputDebugString(Buffer);
#endif
    }