A factory reset, also known as master reset, is a software restore of an electronic device to its original system state by erasing all of the information stored on the device in an attempt to restore the device to its original manufacturer settings. Doing so will effectively erase all of the data, settings, and applications that were previously on the device. This is often done to fix an issue with a device, but it could also be done to restore the device to its original settings. Such electronic devices include smartphones.
Since a factory reset entails deleting all information stored in the device, it is essentially the same concept as reformatting a hard drive. Pre-Installed applications and data on the card's storage card (such as a MicroSD card) will not be erased. A factory reset should be performed with caution, as it effectively destroys all data stored in the unit. Factory resets can fix many chronic performance issues such as freezing and will not remove the device's operating system.
Common reasons to perform a factory reset include:
- to fix a malfunctioning electronic device
- to remove a file or virus that is difficult to remove
- to clear the configuration and settings of the electronic device to the default settings
- to clear the memory space on the electronic device
- to remove personal information from the device before selling, giving away, returning or disposal
Note: a factory reset may only hide data from the operating system so it appears it no longer exists. This is not the same effect as data deletion, and may not therefore be wholly suitable in situations where the device changes ownership.
Factory resets can be achieved in a variety of ways depending on the electronic device. For some devices, this could be done by going into the device's service menu. Other devices may require a complete re-installation of the software. The following section lists a few common electronic devices and how they can be factory reset.
Computer factory resets will restore the computer to the computer's original operating system and delete all of the user data stored on the computer. Microsoft's Windows 8 and Windows 10, and Apple's macOS have options for this.
On Android devices there is a factory data reset option in Settings that will appear to erase all of the device's data and reset all of its settings. This method is typically used when the device has an issue that cannot be fixed using other methods, or when the owner wants to destroy their personal data before selling the device. After performing a study, Avast! reported that the data is recoverable using "fairly generic" and "publicly available" forensics software. The "Factory data reset" option has no effect on the Knox Flag. As such, it does not reset the device to its original factory settings and is not a way to return the device to a state compatible with the manufacturer's warranty. Data on the SIM card and the MicroSD card are not erased. If the device has been modded to a custom recovery such as TWRP that is able to custom install custom roms. Be sure to back up any data as well as the stock rom that is necessary.
Many electronic devices have a menu with tools and settings called the service menu. The service menu commonly includes a tool that performs a factory reset. This tool is most common in devices with displays, such as television sets and computer monitors. These menus are usually accessed through a sequence of button presses.
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- "Service Menu Instructions" (MediaWiki).