Enabling macros in Excel 2007-2010 can be a pain and is not obvious. By default macros are disabled and must be enabled. This is a security feature that stops malicious code from running automatically when you open an Excel file. Malicious macros can erase or corrupt your drives and files and can access private information. This not good.
There are two main steps:
First, make sure your global Macro Security is set to "Disable all macros with notification". This only has to be done once and the setting will be remembered when you close and open Excel and if you shutdown and/or restart you computer.
Second, with the setting on "Disable all macros with notification", you will greeted with a Security Warning each time you open a workbook that contains macros. If you trust the author then click Enable This Content. Leaving the setting at a lower setting will allow any macro to run without a security prompt.
a) Set global Macro-Security to "Disable all macros with notification". This only has to be done once and will be set for all files.
2) Enable Macros