I have this workbook with macros running and programmed to minimize or password to close the workbook .This workbook collects data 24 hours with breaks between shifts. if someone minimized it then started a new workbook, Excel popup indicating that this "macro1" not a variable on this new workbook and closes the original workbook with macros. the second new workbook and the popup can not be close except thru Task Manager. is there a work around and maybe limit excel to one instance?