Wiping Your BlackBerry can solve many problems with Your device, but remember: wiping Your BlackBerry will erase ALL Your data, so it’s recommended to create backup file using BlackBerry Desktop Manager.

To wipe Your device You have to:

From menu choose: Option -> Security Options -> General Options -> Wipe handheld -> Contiunue -> Enter: blackberry

Now it will take some time depending of amount of data stored on Your device.