The most stable and widely used official firmware for the Nokia 500 RM-750 is (Symbian Belle). You can download this official package from sources like Frendx .
These are the core system files and language packs. nokia 500 rm 750 flash file top
The most common software is Phoenix Service Software . Alternatively, boxes like ATF (Advance Turbo Box) or MX Key can be used. The most stable and widely used official firmware