You can update your Nokia 5800 firmware by OTA (Over-The-Air) or via Nokia’s Software Updater application , Ovi Suite on Windows PC . The Nokia 5800 does have UDP (User Data Preservation), but its always a good idea to backup all your personal data before updating the firmware.
Note: It may take some time before the new firmware is available for your region.
Nokia 5800 Changelog :
– Improved Mail for Exchange – Improved video calls – Improved browser – Performance improvements