Let's build a Syncthing MSI package running as a service under local SYSTEM account or LocalService account. This is part of my work to contribute to the Syncthing Project - https://www.syncthing.net
See the wiki articles which explain how you "just need to double click" a batch script and it will automatically build your own MSI package containing the official Syncthing release version you specify.
FIRST HOWTO - Build your own Syncthing MSI
SECOND HOWTO - Optionally personalize the built Syncthing MSI
Helpful discussion with questions and answers on the Syncthing Community Forum: