ensure that only a single instance of maya is running on windows.

oneMaya.vbs

'Be sure that maya's bin folder is located in your system's path.
Dim AllProcess, Process, strFoundProcess
 Dim objShell : Set objShell = CreateObject("Wscript.Shell")
 strFoundProcess = False 
 Set AllProcess = getobject("winmgmts:") 'create object 
 
objShell.Run "maya.exe"
 WScript.Sleep 4000
 Do
     For Each Process In AllProcess.InstancesOf("Win32_process") 'Get all the processes running in your PC 
         If (Instr (Ucase(Process.Name),"maya.exe") = 1) then
             objShell.Run "taskkill /IM maya.exe",1,True 'if app is running
             strFoundProcess = True 
         End If
     Next
 Loop until strFoundProcess = True
 
 If strFoundProcess = False Then 
      objShell.Run "maya.exe"
 End If