If your mobile phone is slow or in any other way doesn't work or respond as well as it should, it may help to restore the factory default settings. This deletes all configurations you've made in your mobile phone.
Find "Security Wipe"
Press the Menu key twice.
Press Security Wipe.
Restore factory default settings
Press Emails, Contacts, etc., User Installed Applications or Media Card.
When the box next to the menu item is ticked (V), the selected data will be deleted.
Press the field and key in blackberry
Wait a moment while the factory default settings are restored.
Follow the instructions on the display to set up your mobile phone and prepare it for use.