When the device is started up the first time after the purchase, there might occur a "memory full" notification in the display within a few minutes after start up. If this happens, do the following steps to solve the issue:
If above does not help, reset the device to the factory settings by entering *#7780# in the dial pad. Before the device is reset, you need to provide the device lock code. The default lock code is 12345.
If still the same issue appears, take a backup by Nokia Suite and format the device by entering *#7370# in the dial pad. Before the device is reset, you need to provide the lock code. Resetting the device will permanently erase all user data and settings as well as add-on applications and operator specific settings.