In PHP I create an XLS-file using COM-object.

```
$excel = new COM("Excel.Application") or die("Excel is not installed!");
$excel->WorkBooks->Add();
...
$excel->WorkBooks[1]->SaveAs($path);
$excel->Quit();
$excel->Release();
$excel = null;

```

After this code has been run, Excel.exe process still be in memory for ~ 6 minutes. How to force this process to quit immediately?