I like to use NSSM (Non-Sucking Service Manager) for executables that aren’t service aware. You can download it here: https://nssm.cc/download
Extract a copy of NSSM.exe and drop it in the same folder with Syncthing.exe. Then open a command prompt from that folder and type this:
nssm install Syncthing
Then browse for the Syncthing.exe and then set the home path with the -home option. Here is a screenshot of how mine is setup:
This seems to be working perfect so far. Even when restarting from the webui.
Edit: Duh, I see NSSM has already come up several times in this thread. Hahaha