HTC S621 - Manual (Page 68)

68 Managing your Phone
4.7 Resetting your Phone
Resetting your phone will remove all the data from its memory which
include contacts, tasks, calendar appointments, and more, and restore the
phone back to the factory default settings.
WARNING! All your data will be deleted, it is recommended that you back up your
data first before resetting your phone.
To reset your phone
1. Click Start > Expert > Clear Storage.
2. Follow the on-screen instructions to reset the phone.
The phone will restart after it has been reset.