Question : Powershell - Excell automation process still runs

I have a script that will open an existing xlsm document and save it back once things are complete. The script works well except that when the file closes an excel.exe process still runs in the background. If I run the script a few times I will have 1 excel.exe process for each. Is there something that I can add to the script to eliminate or prevent the continued process from existing?

I do not want a brute force method though.

thanks in advanced.
C

         
           
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          $a = New-Object -comobject Excel.Application 
    $a.visible = $true
    $path =  "C:\powershell\source\"
    $file1 = get-content "c:\powershell\source\sourcefile.txt"
    $pathFile = $Path + $file1
    $b = $a.Workbooks.Open($pathfile)
    $c = $b.Worksheets.Item(7)






$fs = New-Object -ComObject scripting.filesystemobject
    $absolutepath = $fs.GetAbsolutePathName("c:\powershell\Results\" + $file1)
    $a.application.displayalerts = $false
    $b.saveas($absolutepath)
    $a.quit()

           
         

Answer : Powershell - Excell automation process still runs

Finally found it, you might enjoy reading this:

http://technet.microsoft.com/en-us/library/ff730962.aspx

I found it when I faced the same problem several months ago. Start out at "Uh-oh." and you'll be in the middle of the technical explanation. The short version is that .NET (rather than just PS) doesn't shut the COMObject down properly.

Fun, isn't it? :)

Chris