Microsoft Office Safe Mode allows you to safely use an Office or Office family program that has encountered certain startup problems. When a problem is detected at startup, Office either fixes the problem or isolates it, allowing the program to start successfully.
Automated safe mode
During startup, Office checks for problems such as an add-in or extension that won't start, or a corrupted resource, file, registry, or template. A message is displayed the next time the program is started, identifying the problem and asking if you want to disable the part of the program that has a problem.
A list of disabled items is accessible through the Disabled Items dialog box (About Microsoft <program>, Help menu). You can use this dialog box to enable the listed items. Enabling some items may require you to reload or reinstall an add-in program or reopen a file. Enabling an item does not necessarily fix the root problem; an item that you enable may be placed back on the disabled list the next time you start the program.
User-initiated safe mode
You can open any Office or Office family program in Office Safe Mode by pressing CTRL while you start the program or by using the /safe option when you start the program from the command line.
The following restrictions apply when you open a program in user-initiated Office Safe Mode. (Some items listed below do not apply to all Office or Office family programs.)