How can i backup my users accounts and settings?

[FTP]

Users & groups account are saved to [install path]/Data/[domain name]/users/ and [install path]/Data/[domain name]/groups/, domain settings are saved in [install path]/Data/[domain name],
administrator settings are saved in [install path]/Data/_ADMINISTRATOR, server settings are saved in [install path]/Data.
If you want to back up your whole domain(users and settins),just copy the entire [install path]/Data/[domain name] directory to a safe place. If only for users,
backup the [install path]/Data/[domain name]/users directory. If only for domain settings, backup the files(no directory) in the directory [install path]/Data/[domain name].
After you reinstall the application copy your files or directories back to the new installed directory.