Hard Reset ZTE Blade Q

First method:

1. At the beginning, turn off the phone by holding the Power button.
2. Then press and hold Power + Volume Up button.
3. Release held keys when you see an Adroid image on phone's screen.
4. Hold down the Power button to enter Recovery Mode.
5. Afterward from the menu choose "Wipe Data/Factory Reset" by using Volume buttons to scroll and Power button to select options.
6. Confirm the whole operation by selcting "yes".
7. When the Recovery Mode menu appears again on the screen select option "reboot system now".
8. Success! The hard reset has just been performed

Second method:

1. If the display is off, press the Power key to turn it back on.
2. After that find and select Settings and then go to Backup & reset.
3. Choose the Factory Data Reset.
4. Tap Reset Phone. 
5. Select Erase Everything if you are sure you want to clear all your data. 
6. Well done!

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.