[Jessica Taylor4]

I'm using Avast security to protect my phone. This app can blocks the phone if I need to. If the thief somehow can manage to reset the phone to factory setting, the app will be erase.

Is there a way to prevent the thief from erasing the "phone security apps"?

[B. Diddy]

Welcome back! Which phone do you have? If it has Lollipop or higher, Google has a new antitheft feature where if someone steals your phone and does a factory reset, he will have to enter the correct Google username and password that was previously on the phone in order to proceed with the Setup Wizard. So factory resetting the phone won't allow the thief to use the phone anyway.

[Jessica Taylor4]

Thanks for the reply. I'm using S5 5.1.1(is it lollipop)?

Is that the only way to protect the phone from factory reset?

[B. Diddy]

Yes, 5.1.1 is Lollipop.

You can also use Android Device Manager (google.com/android/devicemanager) to remotely locate, lock, and wipe a phone--but this requires the phone to be on and connected to the web.

[Jessica Taylor4]

I actually test google.com/android/devicemanager, but it didn't Ring/Lock my phone. My phone is currently connected to the internet too.

[B. Diddy]

Can it locate the phone? On the phone, go to Settings>Security>Device Administrators, and make sure Android Device Manager is checked on.