To reinstall FitBit Connect, uninstall the software from your computer, reboot and then run the software's setup file and follow the on-screen instructions. The latest version of the FitBit Connect software installer is available from the FitBit website.
To prevent errors during the installation process, disable your firewall and antivirus software before running the installer, and re-enable them after the installation has completed. Connect your FitBit device to your computer once the installer has finished running, and force it to sync with the service. Enter your account details when prompted by the software. After a successful sync, the software is ready to use.