You can use flash files for flashing your mobile or update mobile old firmware. The developers of nokia company releasing latest updates of all Nokia phones. If your mobile working so slow or completely break at this moment you will need to flash your mobile with its latest flash files. You can use different tools for flashing your mobiles like Phoenix, Nemesis, Ufs Box, Volcano, Turbo Flasher etc. If you wish to flash your mobile without flashing box and want to flash using usb data cable flashing tool phoenix service will help you to do that all. You will need to download phoenix service and install it on your pc and will need to install most needed driver packages.
Remember: Before flashing please don't forget to take backup of your important data because after flashing you will lose your all of data and your mobile will restored in its original settings.
Now you can download latest flash files of your phone from below links