Docm is a new file extension in Word 2007. It is a close cousin to the docx file, but what does the "M" stand for? And why are security warnings popping up when when I try to open the file?
The “M” stands for macro. A macro is a program that is embedded in a Word file used to automate repetitive tasks.
In Word 2007 and 2010, any file that contains a macro must be saved with this file extension.
You can still save a document that contains a macro as a docx file, but the macro will not be saved with the document.
There are security reasons why Microsoft created the new file extension.
A macro is a piece of Visual Basic (VB) programming code that is embedded in the file. This programming code runs a script…which also means if it contains a virus, you allow the virus program to run on your computer.
The new extension alerts you that there is potentially harmful code contained in the document so you can take security precautions when opening it.
This article explains how to:
If you do not own Word (or you own a previous version of Word) and cannot open a macro-enabled file, see the Word Tip How to Open docx Files without Word 2007.
Open a docm file the same way you open any Word file, double-click on the file name or the file icon and the file will open.
Even if you use Word 2007, you may have to change some program settings to use a Microsoft Word macro-enabled document. Overall security settings are changed in the Trust Center.
If you are using Word 2007, but cannot run a macro in a macro-enabled file, check your document security settings. Here is how to access the Trust Center and view or change the settings:
As you can see from the screenshot, I selected Disable all macros with notification. This disables macros in any documents I open unless they are located in a trusted location. (Trusted location settings can be changed by selecting Trusted Locations in the Trust Center.)
If you never expect to open documents that contain macros and want the highest document security settings enabled, select either Disable all macros without notification or Disable all macros except digitally signed macros.
I do not recommend selecting Enable all macros unless you know you are in a closed and secure computing environment (which is not likely).
If you open a document that violates your Trust Center rules, such as a document from an unknown source or one which is not located in a trusted location, the macro will be disabled and a security warning appears.
What happens when you receive a macro-enabled file and you want to run the macro, but Word has disabled it?
Follow these steps to enable the macro:
You can now run Microsoft Word macros that are contained in the docm file.
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