I have installed Syncthing on 3 different Window PCs on 2 it is working great but on the third device I went to start the application up and it is asking for a password on the GUI browser (chrome) but I may have mis-typed the password when configuring and now I can’t get access.
I have looked online how to reset the password but it is not 100% clear to me how to access the config file.
Please check https://docs.syncthing.net/users/config.html for the specific location. You should be able to open config.xml (e.g. with a plain text editor) and clear the password in there. It will be in the gui section somewhere at the bottom of the file.
Or use the syncthing generate --gui-password option from the command line if you don’t want to fiddle around in XML files. See Syncthing — Syncthing documentation