LISTING 4: ChkProcess.vbs
Option Explicit
Stop
On error Resume Next
'==================
'Declarations
'==================
Dim user,domain
Dim wshShell
Dim strUserName
Dim loc
Dim svc
Dim proc_list
Dim proc
Dim ret
Dim oArgs
Dim Program
Dim Target
Dim Start
'==================
'Main Body
'==================
Set oArgs =WScript.Arguments
set loc = createObject("WbemScripting.SWbemLocator")
Set wshShell = CreateObject("Wscript.Shell")
Program = oArgs(0)
Target = oArgs(1)
strUserName = wshShell.ExpandEnvironmentStrings("%Username%")
loc.security_.impersonationLevel = 3 'impersonate
set svc = loc.connectServer(".","root\cimv2")
set proc_list = svc.ExecQuery("Select * from Win32_Process")
for each proc in proc_list
 ret = proc.GetOwner(user,domain)
 if ret <> 0 then
  'wscript.echo "Error executing GetOwner for process " & proc.Name & " ,Error value = " & ret
 Else
 	If proc.name = Program then
  		If strUserName = user then
  			MsgBox user & " is already running " & Program & " ... You cannot open another 
instance",vbexclamation,"Warning"
  			WScript.quit
  		End If
  	End If
  	
 end if
next

start = WshShell.run(Target)