Prevent Macro from running on Open Event

Some of the macros written under Auto_Open or Workbook_Open procedure will run as the file is opened.

If you have set your macro security level to low, all the files tend to open without any notification and will run the macro on Open event.

Easy way to stop this is to hold "Shift" key while opening the file. This will disable them.

If you have set your macro security level to medium, then you can stop the macro from running by clicking on "Disable Macros" option in the notification on Open.

Please note that "Disable Macros" disable all the macros in the workbook.