It's possible, but not with the function _Singleton, check this out >> plus, be aware that the return values differ from _Singleton, if no process is currently running it returns 0, otherwise the PID. Also it only uses 0 & 1 for the flags as 2 doesn't apply to this function. Local $iSingleton = _SingletonPID('RandomName', 1) If $iSingleton = 0 Then MsgBox(4096, '', 'This is the first instance of the program running: ' & $iSingleton) Else MsgBox(4096, '', 'There is another