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Syncthing Windows Setup

Syncthing Windows Setup is a lightweight yet full-featured Windows installer for the open-source Syncthing file-synchronization application.

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Table of Contents

• System Requirements
• Download
• Background
• Version History
• Upgrade Details
• Downgrading an Installation
• Changing Installation Type
• Setup Initialization Errors
  • Installation for All Users not Allowed on Domain Controllers
  • Invalid WSH Script Registration
  • Administrative Installation Detected
• Setup Command Line Parameters
• Offline Installation
• Non Administrative vs. Administrative Installation Mode
  • Non Administrative (Current User) Installation Mode
  • Administrative (All Users) Installation Mode
    • Windows Service Installation
    • Local User Service Account Considerations
    • Granting Folder Permissions for the Service Account
• Setup Tasks
• Start Menu Shortcuts
• Managing Automatic Startup
  • Managing Automatic Startup for the Current User
  • Managing Automatic Startup for the Windows Service (All Users)
• Checking If Syncthing Is Running
  • Checking if Syncthing is Running for the Current User
  • Checking if Syncthing is Running as a Service
• Windows Firewall Rules
  • Firewall Rule Creation
  • Creating the Firewall Rule Manually
  • Firewall Rule Removal
  • Removing the Firewall Rule Manually
• Helper Tools
• Resetting the Service Account Password
• Finding the Syncthing Configuration Folder
• Uninstalling Syncthing
• Silent Install and Uninstall
  • Silent Non Administrative (Current User) Installation
  • Silent Administrative (All Users) Installation
  • Silent Uninstall
• Reporting Problems
• Acknowledgments

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System Requirements

Syncthing Windows Setup has the same requirements as Syncthing itself: Windows 10 or Windows Server 2016 or later.

Download

You can download the latest version of Syncthing Windows Setup from the Github Releases page:

https://github.com/Bill-Stewart/SyncthingWindowsSetup/releases/latest/

Background

Syncthing Windows Setup (herein referred to as "Setup") provides a Syncthing installer for Windows, built using Inno Setup. It provides the following features:

• Downloads and installs the latest version of Syncthing from GitHub

• Supports offline installation for Windows-based computers that can't connect to GitHub (see Offline Installation)

• Supports non administrative (current user) and administrative (all users) installation (see Non Administrative vs. Administrative Installation Mode)

• When installing for the current user (the default), Setup creates a scheduled task that starts Syncthing at logon (if selected)

• When installing for all users, installs Syncthing as a Windows service (see Windows Service Installation)

• Supports adding a Windows Firewall rule for Syncthing (see Windows Firewall Rules)

• Installs a set of helper tools for ease-of-use (see Helper Tools)

• Supports silent (hands-free) installation (see Silent Install and Uninstall)

• Allows localization of Setup and scripts (see building.md file for details)

Version History

See history.md.

Upgrade Details

Administrative installations in versions 1.19.1 and older configured the Windows service to run using the Windows built-in LocalService account. To improve security, Setup versions newer than 1.19.1 configure the Windows service to run using a local service user account instead (SyncthingServiceAcct by default). As a part of this change, the Syncthing configuration data is now located in the CommonAppData\Syncthing folder (e.g., C:\ProgramData\Syncthing).

If you upgrade an administrative installation from version 1.19.1 or older, Setup version 1.27.0 and newer will uninstall the old version and install the new version, but it will no longer migrate the configuration data. Because of this change, it is recommended to first upgrade to version 1.26.1 to migrate the configuration data, and then upgrade again to version 1.27.0 or later.

Starting in version 1.27.11, Setup automatically downloads and installs the latest version of Syncthing for Windows from GitHub. If Setup can't connect to GitHub, you must perform an offline installation (see Offline Installation).

Downgrading an Installation

To downgrade a Syncthing installation, do the following:

1. Disable Syncthing's automatic upgrade setting.

2. Stop Syncthing.

3. Manually replace the syncthing.exe file with your preferred version.

4. Start Syncthing.

NOTE: If you run Setup to reinstall or upgrade Syncthing, the Automatic upgrade interval setting on the Select Configuration Settings wizard page (or the /autoupgradeinterval command-line parameter) will override the Automatic Upgrades setting in the Syncthing configuration GUI.

Changing Installation Type

If you installed using non administrative (current user) installation mode and want to use administrative (all users) installation mode instead (or vice versa), you must uninstall and reinstall using your preferred installation mode.

If you want to keep the same configuration, you will need to replace the content of the Syncthing configuration folder. The location of the Syncthing configuration folder depends on the installation mode; see Finding the Syncthing Configuration Folder for details.

Setup Initialization Errors

This section discusses potential errors that may occur during Setup's initialization phase that will abort the installation process.

Installation for All Users not Allowed on Domain Controllers

For various reasons, Setup does not permit installation for all users (i.e., the Windows service) on Active Directory domain controller servers. If you need to run Syncthing on domain controllers, this author's recommendation is to run syncthing.exe using a Group Managed Service Account (gMSA). See Microsoft's documentation for more information about gMSAs.

Invalid WSH Script Registration

Setup uses Windows Script Host (WSH) scripts to perform a number of tasks. On some computers, the WSH script registration for JScript (.js) files on the computer is missing or incorrect. To ensure it can complete successfully, Setup checks for the following value in the registry:

Path: HKEY_CLASSES_ROOT\.js
Default value: JSFile

Setup will abort if this registry value is not correct. To fix this problem, use whatever tool you prefer (e.g., the Windows Registry Editor) to correct the default value at this registry location to JSFile. For example, you can run the following command from an elevated command line (cmd.exe or PowerShell) window:

reg add "HKCR\.js" /ve /d "JSFile"

Administrative Installation Detected

If Setup detects that the package is installed in administrative (all users) installation mode and you did not specify the /allusers parameter on Setup's command line, it will abort the installation and instruct the user to restart setup with the /allusers parameter.

Setup Command Line Parameters

The following table lists the most common Setup command line parameters:

Parameter | Description --------- | ----------- /currentuser | Runs Setup in non-administrative (current user) installation mode (see Non Administrative vs. Administrative Installation Mode). This is the default and is recommended for most users. /allusers | Runs Setup in administrative (all users) installation mode (see Non Administrative vs. Administrative Installation Mode). This installs the Windows service and is recommended for more advanced users. NOTE: You must specify this parameter if performing a reinstall in administrative (all users) installation mode, even if the package is already installed. /dir="location" | Specifies the installation folder. The default installation folder depends on whether Setup runs in administrative (all