Safe mode is a function mode available in many operating systems, electronics, and software programs in which the device or program has limited functionality to allow the user to focus on performing diagnostic tests. The stripped-down nature of this operating mode is also designed to be safer for the user, as the term “safe mode” implies, since problems and conflicts which can cause errors are generally not loaded when a program is started in this mode.
One of the most classic reasons to start a device or program in safe mode is if the device is not working properly. By restarting in this mode, the user can look for the cause of the problem. For example, a user might have installed a new add-on to a software program which conflicts with the program's normal operations, causing errors. By opening the software in a safe mode, the user ensures that the new add-on doesn't automatically load, which means that the errors will not occur while the user diagnoses the problem.
Operating systems can be started in safe mode to allow people to get rid of malware and viruses which load automatically at startup, or to deal with conflicts caused by the installation of new devices or programs. Many operating systems and electronics are also designed to boot into a safe or limited mode if there is a fundamental system error.
Safe mode has limited functionality, because the system usually turns on a minimum of devices and programs. However, it can take longer to start up, because the device usually tests itself in the process of booting to look for compromises in the system. Users should be aware that sometimes an operating system, software program, or electronic device can look like it is “hanging” while starting up in this mode.
Software programs have a variety of ways to access safe mode, and it's useful to know how to start in a safe or diagnostic mode in case of a problem. In the case of operating systems, Windows systems enter safe mode when the user taps the F8 key during startup, which allows the user to enter a menu which can be used to direct the computer to boot in safe mode. Apple users can hold down the shift key during startup to get into safe mode. It is also possible to boot into this mode with the use of rescue discs, many of which are provided with new computers.