1. Start Regedit and optionally navigate to Computer\HKEY_CURRENT_USER\SOFTWARE\LibreCAD
2. File, Export, Ensure selected branch is HKEY_CURRENT_USER\SOFTWARE\LibreCAD, enter Filename eg MyLibreCadSettings, Save
LibreCad settings can easily be restored by double clicking on the *.reg file and prompts will appear to open RegEdit if required and to add the contents of the file to the registry.