How to format your android system

1
Backup your media and data. Reformatting the Android device will erase all of the data stored on it. Make sure that you have backups of any important files, pictures, documents, videos, or anything else you want to keep.


Your app purchases are tied to your Google account, and will be available for re-download when you sign in to your formatted device.
See this guide for details on backing up your device's settings.
See this guide for details on transferring files from your device to your computer.
2
Open your device's Settings menu. You can access this from the Settings app, or by pressing your phone's Menu button and then selecting Settings.
3
Tap "Backup & reset". This will open the menu that allows you to reset your phone.

4
Tap "Factory data reset". You will be asked to confirm that you want top reset the phone. once you confirm, the phone will start the reset process. When the process is complete, your phone will be like it was new out of the box.
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Method Two of Two:
Resetting a Non-Working Android

1   Boot your phone into Recovery Mode. If your Android device will not boot normally, you can perform a factory reset from the Recovery boot menu. Press and hold the correct buttons while your phone is powered off. The buttons vary from device to device.[1]
Nexus devices - Volume Up, Volume Down, and Power
Samsung devices - Volume Up, Home, and Power
Moto X - Volume Down, Home, and Power
2   Select "recovery". Use the volume buttons to scroll through the menu options. Select "recovery" from the list, and then press the Power button to select it.
3   Select "wipe data/factory reset". Confirm that you want to reset the phone by selecting "Yes - delete all user data". Your phone will now begin the reset process.