Installing FreeFTPd to run as a service
FreeFTPd is a fantastic lightweight FTP and SFTP server that runs on Microsoft Windows. Download it from here https://www.freesshd.com/index.php?ctt=download
The installer is under 1MB in size and installation to run as a service is extremely simple. Just click through the installation wizard and once it has installed and private keys have been generated it will prompt you ‘Do you want to run FreeFTPd as a system service?’