A hard reset of the Blackberry Curve 8520 sets the mobile phone's [configuration] to default settings and erases all the content in the Blackberry. All data including messages, contact list, images, audio, video and any other information will be lost. It is recommended to take a backup of the data before making a hard reset of the Blackberry Curve 8520 mobile phone. The hard reset of the Blackberry Curve 8520 can be done quite simply by selecting the "Erase All Content" option from the General Settings Menu of the Blackberry.
To perform a hard reset under a Blackberry Curve 8520:
Go to Menu> Option> Security Options> General Settings> Menu and then select "Erase All Content". As the name implies, all data will be lost. Make sure you have a backup of the BlackBerry before this operation.