Microsoft Excel 2010 : Macros and UDFs - Enabling VBA Security

Security settings can be set for all workbooks or for specific, trusted locations. Workbooks stored in a folder that is marked as a trusted location will automatically have its macros enabled.

Macro settings are found under File, Options, Trust Center, Trust Center Settings, Macro Settings. The four macro setting options are

• Disable All Macros Without Notification— Prevents all macros from running. With this setting, only macros in the Trusted Locations folders can run.

• Disable All Macros with Notification— The recommended setting. A message is displayed in the Message Area that macros have been disabled. You can choose to enable the content by clicking that option, as shown in Figure 1.

  Figure 1. The Disable Macros with Notification settings gives you control over whether to allow macros to run.

  

• Disable All Macros Except Digitally Signed Macros— Requires you to obtain a digital signing tool from VeriSign or another provider. Appropriate if you are going to be selling add-ins to others, but a bit of a hassle if you just want to write macros for your own use.

• Enable All Macros (Not Recommended: Potentially Dangerous Code Can Run)— Although this option requires the least amount of hassle, it opens your computer to attacks from malicious Melissa-like viruses. Microsoft suggests that you do not use this setting.

The recommended macro setting is Disable All Content with Notification. With this setting, if you open a workbook that contains macros, you’ll see a Security Warning in the area just above the formula bar, as shown in Figure 13.1. Assuming you were expecting macros in this workbook, click Enable Content.

If you do not want to enable macros for the current workbook, dismiss the Security Warning by clicking the X at the far right of the message bar.

If you forget to enable the macros and attempt to run a macro, a message informs you that you cannot run the macro because all macros have been disabled. You will need to close the workbook and reopen it to access the message bar again and enable the macros.

After you enable macros for a workbook stored on a local hard drive and then save the workbook, Excel will remember that you previously enabled macros in this workbook. The next time you open this workbook, macros will be automatically enabled.

Developer Tab

By default, the Developer tab is hidden in Excel. The Developer tab contains useful tools, such as buttons for recording macros and adding controls to sheets. To access it, do the following:

1.	Go to File, Options, Customize Ribbon.
2.	In the right list box, select the Developer tab, which is near from the bottom.
3.	Click OK to return to Excel. Excel displays the Developer tab shown in Figure 2. Figure 2. You’ll need the Developer tab to access tools specific to macros.

The buttons in the Code group on the Developer tab are used for recording and playing back macros:

• Visual Basic— Opens the Visual Basic Editor (VB Editor or VBE).

• Macros— Displays the Macro dialog, where you can choose to run or edit a macro from the list of macros.

• Record Macro— Begins the process of recording a macro.

• Use Relative Reference— Toggles between using relative or absolute recording. With relative recording, Excel will record that you move down three cells. With absolute recording, Excel will record that you selected cell A4.

• Macro Security— Shortcut to access the Trust Center, where you can choose to allow or disallow macros to run on this computer.