Safe mode is a

diagnostic Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...

mode of a computer

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

(OS). It can also refer to a mode of operation by

application software Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as ...

. ''Safe mode'' is intended to help fix most, if not all, problems within an operating system. It is also widely used for removing rogue security software.

Background

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

, Android and

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

distributions such as

Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed primarily of free and open-source software. Developed by the British company Canonical (company), Canonical and a community of contributors under a Meritocracy, meritocratic gover ...

and

Linux Mint Linux Mint is a community-developed Linux distribution. It is based on Ubuntu and designed for x86-64 based computers; another variant is based on Debian which is named Linux Mint Debian Edition (LMDE) and has both 64-bit and IA-32 support. T ...

are examples of contemporary operating systems that implement a safe mode as well as other complex

electronic devices Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other electrically charged particles. It is a subfield of physics and ...

. In safe mode, an operating system has reduced functionality, but the task of isolating problems is easier since many non-core components are disabled, such as sound. An installation that will only

boot A boot is a type of footwear. Most boots mainly cover the foot and the ankle, while some also cover some part of the lower calf. Some boots extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearl ...

into safe mode typically has a major problem, such as disk corruption or the installation of poorly-configured software that prevents the operating system from successfully booting into its normal operating mode. Though it varies by operating system, safe mode typically loads only essential executable modules and disables

devices A device is usually a constructed tool. Device may also refer to: Technology Computing, electronics, mechanisms and telecommunication * Appliance, a device for a particular task * Computer, a computing device * Device file, an interface of a pe ...

except for those necessary to display information and accept input. It can also take the form of a parallel "miniature" operating system that has no configuration information shared with the normal operating system. For example, on Microsoft Windows, the user can also choose to boot to the

Recovery Console The Recovery Console is a feature of the Windows 2000, Windows XP and Windows Server 2003 operating systems. It provides the means for administrators to perform a limited range of tasks using a command-line interface. Its primary function is to ...

, a small text-based troubleshooting mode kept separate from the main operating system (which can also be accessed by booting the install CD) or to various "safe mode" options that run the dysfunctional OS but with features, such as video drivers, audio, and networking, disabled. Safe mode typically provides access to utility and diagnostic programs so a user can

troubleshoot Troubleshooting is a form of problem solving, often applied to repair failed products or processes on a machine or a system. It is a logical, systematic search for the source of a problem in order to solve it, and make the product or process ope ...

what is preventing the operating system from working normally. Safe mode is intended for maintenance, not functionality, and it provides minimal access to features.

Operating systems

Windows

Microsoft Windows' safe mode (for 7/

Vista Vista may refer to: Software *Windows Vista, the line of Microsoft Windows client operating systems released in 2006 and 2007 * VistA, (Veterans Health Information Systems and Technology Architecture) a medical records system of the United States ...

/ XP /

2000 2000 was designated as the International Year for the Culture of Peace and the World Mathematics, Mathematical Year. Popular culture holds the year 2000 as the first year of the 21st century and the 3rd millennium, because of a tende ...

/ ME/ 98/ 95) is accessed by pressing the F8 key as the operating system boots. Also, in a multi-boot environment with multiple versions of Windows installed side by side, the F8 key can be pressed at the OS selector prompt to get to safe mode. However, under Windows 8 (released in 2012), the traditional press-F8-for-safe-mode-options UI convention no longer works, and either Shift-F8 or a special GUI-based workaround is necessary.

Unix

An equivalently minimal setting in

Unix-like A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...

operating systems is single-user mode, in which daemons and the

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...

are not started, and only the

root user In computing, the superuser is a special user account used for system administration. Depending on the operating system (OS), the actual name of this account might be root, administrator, admin or supervisor. In some cases, the actual name of the ...

can

log in In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system or program by identifying and authenticating themselves. Typically, user credentials ...

. It can do emergency repairs or maintenance, including resetting users' passwords on the machine without the need to know the old one.

macOS

In addition to single-user mode, macOS also supports safe mode; holding the shift key after powering up activates Safe Boot, which has background maintenance features (Besides the mode selection, it runs a file system repair, and in Mac OS X 10.4, it disables all fonts other than those in /System/Library/Fonts, moves to the Trash all font caches normally stored in /Library/Caches/com.apple.ATS/(uid)/, where (uid) is a user ID number such as 501, and disables all startup items and any Login Items). Unlike in Windows where safe mode with networking is disabled by default and requires using a safe mode with networking enabled, in the macOS Safe Boot always includes networking. On the

Classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and end ...

versions 6, 7, 8, and 9, a similar mode to Safe Mode is achieved by holding down the

shift key The Shift key is a modifier key on a alphanumeric keyboard, keyboard, used to type majuscule, capital letters and other alternate "upper" characters. There are typically two Shift keys, on the left and right sides of the row below the home row. T ...

while booting, which starts the system without

extensions Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (proof theory) * Extension (predicate logic), the set of tuples of values t ...

iOS

iOS Ios, Io or Nio (, ; ; locally Nios, Νιός) is a Greek island in the Cyclades group in the Aegean Sea. Ios is a hilly island with cliffs down to the sea on most sides. It is situated halfway between Naxos and Santorini. It is about long an ...

does not have a safe mode, however some jailbreaks add a safe mode where all tweaks are disabled, the wallpaper is black and a notification will tell you that you are in safe mode. In that mode, some apps may not launch.

Android

The way that safe mode in Android can be activated differs per vendor. Safe mode can be disabled by rebooting the device. When you reboot into safe mode in Android, downloaded apps and widgets are automatically disabled, but built-in apps remain available. A watermark in the bottom-left corner also appears if you're booted to either normal or safe mode. Some devices also turn their radios off automatically upon booting into safe mode.

Application software

Application software Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as ...

sometimes offers a safe mode as well. In the

PHP PHP is a general-purpose scripting language geared towards web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by the PHP Group. ...

interpreter Interpreting is translation from a spoken or signed language into another language, usually in real time to facilitate live communication. It is distinguished from the translation of a written text, which can be more deliberative and make use o ...

, prior to version 5.4, safe mode offers stricter security measures. The

Glasgow Haskell Compiler The Glasgow Haskell Compiler (GHC) is a native or machine code compiler for the functional programming language Haskell. It provides a cross-platform software environment for writing and testing Haskell code and supports many extensions, libra ...

from version 7.2 offers "Safe Haskell" mode, restricting usage of functions such as unsafePerformIO.

Mozilla Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements curren ...

's safe mode allows the user to remove

which may be preventing the browser from loading.

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a deprecation, retired series of graphical user interface, graphical web browsers developed by Microsoft that were u ...

can run in "No Add-Ons" mode and Protected Mode.

Cydia Cydia is a graphical user interface of APT for iOS. It enables a user to find and install software unauthorized by Apple on jailbroken iPhones, iPads and iPod Touch devices. It also refers to the digital distribution platform for software on ...

's MobileSubstrate also has a safe mode that allows the user to uninstall tweaks and extensions that may crash the SpringBoard.

Minecraft ''Minecraft'' is a 2011 sandbox game developed and published by the Swedish video game developer Mojang Studios. Originally created by Markus Persson, Markus "Notch" Persson using the Java (programming language), Java programming language, the ...

has a safe mode that activates if a player attempts to open a world with an invalid data pack, which gives the option to load the world using only the vanilla data pack.

References

{{reflist

External links

Mac OS X: Starting up in Safe Mode
Booting