Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.!
Reset the BlackBerry 9900 reset
Remove and reinsert the battery.
BlackBerry 9900 Bold Touch Hard reset
Select All > Options > Security. Select Security Wipe. Enter "blackberry" in the text field to confirm. Tap Wipe Data.
From menu select Menu key > Options > Security Options > Security Wipe > Enter "blackberry" (without quotes) then press the Wipe button on screen.
To delete data from the messages application, contacts application, and other applications, select the Emails, Contacts, Etc check box.
To delete all third-party applications that you have added, select the User Installed Applications check box.
To delete all files from your media card, select the Media Card check box.