how to hard reset Acer E400

Resetting your Acer E400 smartphone

Resetting your smartphone
You may have to perform a reset if your smartphone fails to respond when buttons are pressed or the screen is tapped.
Pressing the Reset button interrupts power and restarts the smartphone; it will not erase personal information, but you may lose information from open applications. The Reset button is found under your smartphone’s battery cover, next to the SIM slot.
Note: Before performing a reset, ensure that your smartphone is not locked. Press any
key or tap the screen to see if the phone responds.

Acer E400 Clean boot

A clean boot will restore your smartphone to the factory settings.
Warning! You should only perform a clean boot when all other options have failed to
restore your smartphone to an operational state.
Warning! This will erase all your personal information, any contacts stored on your
phone and any programs you installed.
It will not erase information from the microSD memory card.
Open Settings from the Applications tab, then tap Privacy > Factory data reset; click Reset phone and then Erase everything to format your phone.
If your phone is not responding to screen input, you may need to reset your smartphone first (described above).