At some point, you’re probably going to have to reset your Samsung Galaxy S3 smartphone. When it’s frozen and not responding, you will want to soft reset it. If you are having major issues with the device that normal troubleshooting doesn’t fix, you may want to hard reset it to factory defaults. Here’s how you can do both.
Whenever the device is frozen or doesn’t respond to commands, simply press and hold the Power button on the device for about 10 to 20 seconds. Eventually, the screen should turn off. You will then be able to turn the device back on and resume normal operation.
There are two ways you can perform a hard reset on the Galaxy S3. One procedure can be done from startup, the other from within the Android OS. These steps will wipe all data from the device, so be sure to have a backup in place if you wish to keep your data. Also, if you have encrypted the data on your SD card, be sure to disable encryption before these steps. Otherwise, you will never be able to view your encrypted files again.
From Android OS
Tap Settings > Back up and reset > Factory data reset > Reset device > Reset everything.
1. With the device powered off, press and hold both Volume buttons, then press and hold Power.
2. Hold all three buttons until you see the screen come on.
3. From the recovery screen, use the Volume Down button to toggle the selection to wipe data / factory reset.
4. Press the Home button to select the highlighted option.