Tracking with windows services

Hi there I'm trying to track, when a specific word files opens with windows services with these below technique but these Methods aren't working in windows services please help me, provide me a through which I can achieve that.

 1. Dim wordApp As Microsoft.Office.Interop.Word.Application
          wordApp = Marshal.GetActiveObject("Word.Application")

Exception occurred: Operation unavailable (Exception from HRESULT: 0x800401E3 (MK_E_UNAVAILABLE)) 
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 2. Dim p() As Process = Process.GetProcessesByName("winword")     
        For Each a In p
            FileRecord.WriteLine("Name : {0}", a.MainWindowTitle)
            'Above Line Write empty a.MainWindowTitle
        Next