Digital Signature of Files Script

Could someone please assist in this script. It appears to run ok, but throws an error about a process in use. What this script does is checks for digital signatures in files.
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Dim objFSO
Dim objStream

Set objFSO = createobject("scripting.filesystemobject")
Set objStream = objFSO.CreateTextFile("C:\DigSigs\test.txt", True)

Set objSigner = WScript.CreateObject("Scripting.Signer")
blnShowGUI = False
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFolder = objFSO.GetFolder("C:\DigSigs")
Set colListOfFiles = objFolder.Files
For each objFile in colListOfFiles
blnIsSigned = objSigner.VerifyFile(objFile.Name, blnShowGUI)
If blnIsSigned then
objStream.Writeline strLine & objFile.Name & " has been signed."
Else
objStream.Writeline strLine & objFile.Name & " has not been signed."
End If
Next

WScript.Quit(0)