cFosSpeed stores its settings in the following files:
You can backup all 5 files.
In addition, if you want to keep the online budget log files you should backup the subdirectory logs: C:\ProgramData\cFos\cFosSpeed\logs.
To restore the settings just restore global.ini, user.ini, data.ini. Settings.ini is overwritten by new installations. Therefore if you also made changes in settings.ini, you need to apply these again in the new settings.ini. Otherwise use the settings.ini from the most recent installed version.