I have used _Singleton function in my script to restrict only one instance to run.
For testing, I have written below code, and triggered multiple instances.
#include <Misc.au3>
MsgBox(0,"",@ScriptName)
if _Singleton(@ScriptName, 1) = 0 Then
Msgbox(64, @ScriptName, "The program is already running.")
Exit
Else
MsgBox(0,@ScriptName,"No other instances running")
EndIf
But all are going to else block.
Please suggest.