''Objects
set shell = createObject("wscript.shell")
Set objFSO = CreateObject("Scripting.FileSystemObject")
 
 
''Check the args passed into the script. Specifically looking for the last argument which is the script mutex
Set args = Wscript.Arguments
argsFound = false
For Each arg In args
	argsFound = arg
Next
 
''If we didn't get any arguments re-run self with a random arg string, this will be the mutex
if argsFound = false then
	runSelf(genRndStr(8))
Else
 
	''The last argument is the mutex string
	mutex = argsFound
end if 
 
''remove any other instances of this script
killPastInstances(mutex)
 
 
 
''This sub will kill all instnances of the currently running vbscript that are running under the same interpreter
''but it will not kill it's self
''note, this requires that this script has a uniquite mutex
sub killPastInstances(mutex)
 
	''Get self name
	scriptName = WScript.ScriptFullName
 
	Set objWMIService = GetObject("winmgmts:\\.\root\CIMV2") 
	Set colItems = objWMIService.ExecQuery("SELECT * FROM Win32_Process",,48) 
	For Each objItem in colItems 
 
		if instr(objItem.CommandLine, scriptName) > 0 Then
		  ''If the instance of the script is NOT this instance
		  if not instr(objItem.CommandLine, mutex) > 0 then
 
		  	''Kill it!
		  	objItem.Terminate()
		  end if
		end if
	Next
end sub
 
 
''generates a random string of length "count"
Function genRndStr(Count)
    Randomize
    For i = 1 To Count
        If (Int((1 - 0 + 1) * Rnd + 0)) Then
            genRndStr = genRndStr & Chr(Int((90 - 65 + 1) * Rnd + 65))
        Else
            genRndStr = genRndStr & Chr(Int((57 - 48 + 1) * Rnd + 48))
        End If
    Next
End Function
 
 
''re-runs the curernt script with args in cscript if it is running in wscript. current script exits
sub forceCscript
  If Instr(1, WScript.FullName, "CScript", vbTextCompare) = 0 Then
 
	Set args = Wscript.Arguments
	argStr = ""
	For Each arg In args
		argStr = argStr & " " & arg
	Next
 
    Shell.Run "cscript """ & WScript.ScriptFullName & """" & argStr, 1, False
    WScript.Quit
  End If
end sub
 
 
 
''Runs a new instance of the current script with additional arguments. Current script exits
sub runSelf(extraArgStr)
 
	''Are we runing in C or W script?
	interpreter = "wscript.exe"
	If Instr(1, WScript.FullName, "CScript", vbTextCompare) = 0 Then
		interpreter = "wscript.exe"
	else
		interpreter = "cscript.exe"
	end if
 
	''Get current args
	Set args = Wscript.Arguments
	argStr = ""
	For Each arg In args
		argStr = argStr & " " & arg
	Next
 
	''append new args if required
	if extraArgStr <> "" then argStr = argStr & " " & extraArgStr
 
    Shell.Run interpreter & " """ & WScript.ScriptFullName & """" & argStr, 1, False
    WScript.Quit
 
end sub