Acer E101 - Manual (Page 63)

63 Resetting your smartphone
Warning! This will erase all your personal information, any contacts
stored on your phone and any programs you installed.
If your screen responds to stylus input: Go to Start > Utilities >
Default Settings. Read the warning information and enter the
security code in the empty textbox. Tap OK to proceed.
If your screen is not responding to stylus input:
1. Push the Silent button up (the off position).
2. Press and hold the Camera button, then press and release
the reset button.
3. Keep the Camera button pressed until you see the ‘Clean
Boot’ screen.
4. Press the Home button to continue.