Run FreeFileSync's RealtimeSync as a Windows Service with AlwaysUp

How to Run FreeFileSync's RealtimeSync 24/7 as a Windows Service with AlwaysUp

Start RealtimeSync monitoring as soon as your computer boots and keep it running 24x7, unattended in the background. Automatically survive reboots, accidental shutdowns, and other failures


Last Updated on June 15, 2026

FreeFileSync is a free, open source application that helps you to keep folders synchronized. The RealtimeSync component allows you to monitor one of more folders and automatically synchronize files if a folder changes.

Since RealtimeSync isn't deployed as a bulletproof Windows Service out-of-the-box, we'll show you how to have AlwaysUp keep it running all the time.


To install RealtimeSync to run as a Windows Service:

  1. Download and install FreeFileSync, if necessary. That will also install RealtimeSync:

    Install FreeFileSync

  2. If necessary, setup a FreeFileSync configuration and FreeFileSync batch job that monitors your folders and performs the desired synchronization.

    When saving the batch job:

    • Check the Run minimized and Auto-Close options, to suppress the usual progress and summary dialogs.
    • Check Ignore errors, which will prevent error and warning messages from delaying synchronization

    FreeFileSync Batch File Settings

    Those changes will ensure smooth operation in the background, when you're not there to respond to prompts from FreeFileSync.

  3. Download and install AlwaysUp, if necessary.

  4. Start AlwaysUp.

  5. Select Application > Add to open the Add Application window:

    Add Application

  6. On the General tab:

    • In the Application field, enter the full path to the RealtimeSync executable, RealtimeSync.exe. If you have installed FreeFileSync in the default location, this will be:

      C:\Program Files\FreeFileSync\RealtimeSync.exe
    • In the Arguments field, enter the full path to your FreeFileSync batch job (*.ffs_batch).

      Our file is "C:\Sync\SyncDevSource.ffs_batch", so we'll specify that full path in this tutorial. Be sure to place your entire path in quotes if it contains a space.

    • In the Name field, enter the name that you will call the application in AlwaysUp. We stuck with the default (RealtimeSync) but you can enter another name if you prefer.

    RealtimeSync Windows Service: General Tab

  7. Switch to the Logon tab and enter the username and password of the account in which you installed and configured FreeFileSync — probably the account you are logged in to right now. It is very important that RealtimeSync runs in this account to find its settings:

    RealtimeSync Windows Service: Logon Tab

  8. Finally, move to the Startup tab and check the Ensure that the Windows Networking components have started box. This tells AlwaysUp to verify the underlying TCP/IP services before launching RealtimeSync:

    RealtimeSync Windows Service: Startup Tab

  9. We're done setting up RealtimeSync to run as a windows service so click the Save button to record your settings. In a few seconds, an entry for called RealtimeSync (or whatever you called it) will show up in the AlwaysUp window. It's not yet running though, and the state will be "Stopped":

    RealtimeSync Windows Service: Created

  10. To start RealtimeSync from AlwaysUp, choose Application > Start "RealtimeSync".

    The application will start in the background, on the isolated Session 0, and you won't see the usual tray icon on your desktop:

    RealtimeSync Windows Service: Running

    But don't worry, because your files will be synchronized as normal. Please perform a test and confirm that everything's working as expected with RealtimeSync running as a service.

  11. That's it! Next time your computer boots, RealtimeSync will start monitoring and synchronizing your folder immediately, before anyone logs on.

    We encourage you to edit RealtimeSync in AlwaysUp and check out the many other settings that may be appropriate for your environment.

    For example, boost RealtimeSync's priority (if it has a lot of copying to do), send an email if RealtimeSync crashes, prevent your computer from going to sleep, and much more.


RealtimeSync not working properly as a Windows Service?

  • Launch RealtimeSync (or FreeFileSync) from a windows service command prompt to see error messages, reveal startup problems and more.

  • Consult the AlwaysUp Troubleshooter — our online tool that can help you resolve the most common problems encountered when running an application as a Windows Service.

  • From AlwaysUp, select Application > Report Activity > Today to bring up an HTML report detailing the interaction between AlwaysUp and RealtimeSync. The AlwaysUp Event Log Messages page explains the more obscure messages.

  • Browse the AlwaysUp FAQ for answers to commonly asked questions and troubleshooting tips.

  • Contact us and we will be happy to help!

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