From David Rupprechter:
NavZUP is a simple backup solution for MS Dynamics NAV ZUP-files. The zup file, which is saving the client configuration, gets corrupted and all settings have to be set again. Using this tool you can simply backup zup files and restore them when needed. This backup-tool for ZUP-files backups/restores .zup-files and creates a folder named "navzup.bak" in the parent directory of NavZUP.