How to Auto Sync Files to External Hard Drive on Windows PC

Need to automatically sync files to external hard drive

Sync (short for synchronization) keeps files updated across multiple locations. When you sync files to an external hard drive, the files on it match those on your computer—whether new or modified.

This eliminates manual updates while maintaining an up-to-date backup. Auto-syncing also enhances data security, protecting against computer issues like crashes, disk failures, or viruses.

Some users may sync between two external drives in Windows 11/10/8/7 for extra backups. Whatever your goal, you’ll need reliable free external hard drive sync software.

Up till now, you may have many questions, such as, how do I sync files to external hard drive in Windows 10? What is the best free external hard drive sync software? Don't worry about it! You will get all the answers in the following.

Best external hard drive sync software: FREE AOMEI Backupper🏆

If you are looking for the best sync software for external hard drive, consider using AOMEI Backupper Standard. It’s completely free and supports auto sync files to external hard drive or between two external hard drives without any obstacles.

AOMEI Backupper

Best Free Windows File Sync Software

• You are allowed to sync files to various destinations, including local disk, external hard drive, and USB drive. You can even sync a laptop and a desktop.

• You can set a sync task to run daily, weekly or monthly with the "Schedule Sync" feature.

• This software has a clear interface and user-friendly design so that users can understand all the steps easily and quickly.

Download Freeware
Windows 11/10/8.1/8/7

100% Secure

Case 1: Automatically sync PC files to external hard drive

First, connect the external hard drive to your computer and be sure it's recognized. Then, follow the steps below to automatically sync files to external hard drive via AOMEI Backupper.

1. Install and launch AOMEI Backupper Standard. Then, select “Basic Sync” under “Sync” tab.

2. In this window, click “Add Folder” to select the folder(s) on your computer needing sync. Then select a folder on external hard drive as destination location.

3. Set a schedule to auto sync to external hard drive. Click “Schedule Sync”, select daily, weekly, or monthly in the pop-out window and click "OK" to exit.

4. Finally, click “Start Sync” > “Add the schedule and start sync now” to begin the process.

Tips:
• If you set to run the task at a specified time in a day/week/month, you should plug in your external hard drive before the task starts. 
• Except for daily/weekly/monthly sync, you still can sync files during shutdown using "Event Triggers" or automatically sync files between computer and flash drive with "USB Plug in".

Case 2: Sync two external hard drives in Windows 11/10/8/7

First, connect two external hard drives you will use to your computer. Then, follow the steps below to sync files with AOMEI Backupper Standard.

1. Launch AOMEI Backupper Standard, and select “Basic Sync” under “Sync” tab.

2. Select "Add Folder" to locate the files you want to sync on the external hard drive. Then, click the second bar to select another external hard drive as destination.

3. Click "Schedule Sync" and select daily/weekly/monthly to auto sync files. After that, go back to the main page of Basic Sync, and click "Start Sync".

Tips to ensure smooth and reliable syncing

Setting up auto sync to an external hard drive is only half the battle. Here are some essential tips to make sure your sync process stays smooth, efficient, and error-free over the long haul.

✅Enable Automatic Mounting for External Drives

Your sync software can't do its job if the drive isn’t connected. Make sure your external hard drive is set to mount automatically when plugged in.

✅Schedule Syncs During Idle or Off-Hours

Running sync jobs while you're actively using your computer can slow things down, especially if large files are involved. Instead, set your sync to run at night, during lunch breaks, or when the system is idle.

✅Double-Check Your Source and Destination Paths

It’s surprisingly easy to sync the wrong folder—or worse, overwrite important files. Before launching a scheduled sync, verify the source folder (where your files live) and the destination folder (your external drive path). Misconfigured paths are one of the most common causes of lost data.

✅Use Incremental or Mirror Sync Modes

To speed up the process and reduce unnecessary file copying, you may use incremental sync (only copying new or changed files) or mirror sync (making the destination identical to the source). Luckily, AOMEI Backupper supports both modes.

✅Keep Your Backup Drive Healthy

External hard drives can fail just like internal ones. To reduce the risk:

• Use Safely Remove Hardware before unplugging
• Run SMART diagnostics or tools like CrystalDiskInfo or DriveDx
• Consider upgrading to an SSD external drive for faster and more reliable performance

Also, make sure your drive has enough free space—most sync tools need some buffer room to operate efficiently.

Written in the end

AOMEI Backupper is the best free external hard drive sync software that allows you to auto sync files to external hard drive or sync files between two external hard drives in Windows 11/10/8/7/XP/Vista (both 32-bit and 64-bit). Also, you can enable its schedule sync to continuously protect your files.

In addition, its advanced versions provide you with 3 different sync solutions, that is, Real-Time Sync, Mirror Sync and Two-Way Sync. If they are more in line with your needs, you can choose to upgrade to the professional or server version. It all depends on the operating system you are using currently. 

Except for sync, you can use it to create complete system backup, restore system image to new hard drive, and clone hard drive, etc. If you have an AOMEI account, you are able to backup files to AOMEI Cloud. For more features, you can download it to explore for yourself.