How to Resolve Brother MFC-L3720CDW Not Printing from Windows

Many Windows users run into moments when their Brother MFC-L3720CDW simply refuses to print. Maybe the printer is not responding, documents stay stuck in the print queue, or the computer acts like it cannot “see” the printer at all. These problems can be frustrating, especially when you need to print something right away.
One of the most common reasons this happens is that the printer’s internal communication software, often called its system file, becomes outdated, missing, or damaged. These system files help your computer talk to your printer. If these files are not working properly, your computer and printer stop communicating correctly, which leads to printing issues.

This guide explains why this happens and how you can fix it by updating the Brother MFC-L3720CDW system file using plain, easy-to-follow steps. Whether you are new to troubleshooting or already comfortable with your computer, this guide provides a clear path to getting your printer working again.

Before you try the manual steps, it helps to know that there is a simple tool that can update this file for you automatically and without any guesswork.

A Quick and Easy Way to Fix Brother MFC-L3720CDW Printing Issues

If you prefer a fast solution, the easiest option is to use DriverAssist, a tool that checks your computer for outdated or corrupted printer communication files and updates them automatically.
This saves time and avoids mistakes that can happen when downloading or installing the wrong update on your own.

You can download DriverAssist here.

Once installed, the tool scans your computer, finds the correct file for your Brother MFC-L3720CDW, and installs it safely. For many users, this is the quickest way to fix printing and connection issues without having to follow long steps manually.

Why Outdated or Damaged Printer System Files Cause Printing Problems

Your Brother MFC-L3720CDW relies on a small, important file inside Windows that tells your computer how to communicate with the printer. If this file is outdated, damaged, or missing, your computer might send the wrong instructions or no instructions at all.

Here are the most common problems that can appear when this file is not working properly:

• The printer will not respond even though it is turned on
• Printing takes unusually long or never starts
• Windows shows error messages
• The print queue gets stuck
• The computer cannot detect the printer over Wi-Fi or USB

Keeping this system file updated prevents these issues and ensures that Windows and your Brother MFC-L3720CDW can communicate correctly.

How to Update the Brother MFC-L3720CDW System File Manually

If you prefer not to use an automatic tool, you can update the file manually. There are two safe and reliable ways to do this.
The first method is to download the update directly from Brother’s official support website.
The second method uses the built-in Windows Device Manager tool.

Both methods are explained step by step below.

Manual Method 1: Update Through the Brother Support Website

This option ensures you get the correct file directly from Brother’s official resources.
Follow these steps carefully:

Step 1: Go to the Brother Support Page

1. Open your web browser.
2. Search for “Brother MFC-L3720CDW support page” using your preferred search engine.
3. Open the official Brother support link for your printer model.

Step 2: Choose Your Operating System

Once on the support page, you will usually be asked to select your version of Windows.
Choose the Windows version you are currently using. If you are unsure, you can check by:

• Opening the Start Menu
• Typing “About your PC”
• Looking under “Windows specifications”

Step 3: Download the Correct Update File

You will find a list of available downloads, including the communication file.
Download the latest version that matches your Windows system.

Step 4: Run the Installer

When the file finishes downloading:

1. Open your Downloads folder
2. Double-click the update installer
3. Follow the on-screen instructions

During installation, the system may ask you to agree to terms or confirm settings. Click through the prompts until the installation completes.

Step 5: Restart Your Computer

Restarting helps Windows correctly load the new file.
Once the computer restarts, try printing again to see if the issue is resolved.

Manual Method 2: Update Through Windows Device Manager

Device Manager is a built-in tool in Windows that lets you manage and update hardware communication files.
This method can fix situations where the file is damaged but still installed.

Step 1: Open Device Manager

You can open Device Manager by:

1. Right-clicking the Start button
2. Selecting “Device Manager” from the menu

Step 2: Find Your Printer

Inside Device Manager:

• Scroll down until you find either “Printers” or “Print queues”
• Click to expand the list
• Look for “Brother MFC-L3720CDW”

If you do not see your printer, it may appear under “Unknown device” if Windows is having trouble identifying it.

Step 3: Open the Update Option

1. Right-click the Brother MFC-L3720CDW entry
2. Select “Update” from the menu
3. Choose “Search automatically for updated software”

Windows will search your system and the internet for the correct communication file.

Step 4: Follow the Prompts

If Windows finds an update, it will install it automatically.
If Windows reports that the best file is already installed but your printer still does not work, the installed file may be corrupt. You can fix this by reinstalling it manually using the Brother website method above.

Step 5: Restart Your Computer

Restarting helps Windows load any new updates. After the restart, try printing your document to check if the issue has been fixed.

Other Helpful Tips if Your Brother MFC-L3720CDW Still Isn’t Printing

Updating the system file usually fixes most printing problems, but here are a few more things you can try:

Check the Printer Connection

Make sure the printer is:

• Connected securely by USB if using a cable
• On the same Wi-Fi network as your computer
• Powered on with no error lights

Clear the Print Queue

Sometimes Windows gets stuck trying to print old documents:

1. Open the Start menu
2. Type “Printers and scanners”
3. Select your Brother MFC-L3720CDW
4. Choose “Open queue”
5. Remove all documents

Try printing again afterward.

Restart Both the Printer and Your Computer

A simple restart can clear temporary issues.

Check for Windows Updates

Windows updates sometimes include improvements for printing.
Go to Settings, then Windows Update, then click “Check for updates.”

Why Using DriverAssist Saves Time

Following manual steps works, but it can be slow, especially if you are unsure which file is correct. DriverAssist removes this guesswork by:

• Scanning your computer automatically
• Detecting any missing, outdated, or damaged printer communication files
• Installing the correct update
• Preventing future printing issues caused by outdated files

It is the easiest way to fix your Brother MFC-L3720CDW if you want a quick solution.
Download it here.

Final Thoughts

Getting your Brother MFC-L3720CDW back to printing normally does not have to be frustrating. The issue often comes from a communication file that is outdated, damaged, or missing. Using DriverAssist is the easiest and fastest fix. If you prefer the manual approach, the Brother support website and Windows Device Manager both offer reliable ways to update the file on your own.

With the steps in this guide, you can restore your printer and avoid similar issues in the future.