Foolishly relocated .exe - how can I reload config / restore ID?

Oh dear. I’m afraid it didn’t work. I copied all the files from C:\Users\William\AppData\Local\Syncthing to Windows/System32/config/systemprofile/AppData/Local/Syncthing and the GUI appears blanked of all particulars. Instead of the name of the computer, it shows (unknown device) and when I pull down the gear icon to Show ID, the field is blank. The Settings opens no window at all.

If I try to restart, it hangs forever on the “Please wait…” notice.

Perhaps I do have to reinstall and start over?