Sony xperia x2 hard reset here is the procedure

There is a boot menu that allows you to do the hard reset (or reset to factory defaults) without using Phone Reset utility.

1. Remove the battery
2. Reinsert the battery, be ready to press two keys on the keyboard
3. Once back-light goes on, within 1 second press and hold win-key (top left) and O.
4. In the menu press W to select clean boot
5. Press Win-key to boot the phone.