When you start up an Excel workbook that contains macros you may see a series of warnings. These warnings are designed to protect your computer from malicious code that if executed could cause irreparable damage to your computer.
If you do not trust the source of the Excel workbook then do not "Enable" the content and your computer will remain safe from any potential threats.
If you do trust the source of the Excel workbook then use the guide below to "Enable" the macro's and start using the added functionality.
Enable Macros Excel 2013:
On first opening the workbook you may see the following warning
Click on 'Enable Editing' to open the workbook for updates
If this warning is presented then Click on 'Enable Content' to access the workbook
Note: If this warning is be presented each time the workbook is opened it can be removed by moving the workbook to a trusted location on your computer. Refer to the solution on Trusted Locations
Enable Macros Excel 2010:
On first opening the workbook you may see the following warning
Click on 'Enable Editing' to open the workbook for updates
If this warning is presented then Click on 'Enable Content' to access the workbook
Note: If this warning is be presented each time the workbook is opened it can be removed by moving the workbook to a trusted location on your computer. Refer to the solution on Trusted Locations
Enable Macros Excel 2007:
On first opening the workbook you may see the following warning
or 
Click on check box to 'Enable this Content' the Click 'OK'
Note: If this warning is be presented each time the workbook is opened it can be removed by moving the workbook to a trusted location on your computer. Refer to the solution on Trusted Locations