How To Windows

How to Fix Arduino Port Not Showing Up or Not Detected on Windows 11

By Arpita 5 min read
Recommended: Download Windows Speedup Tool to quickly fix PC issues.

You just plugged in your Arduino board to your PC, but the COM port isn’t showing up — no matter what you try. The Arduino IDE might show an error like “Board at COMx not found” or the Tools > Port menu is greyed out.

Don’t worry — this is one of the most common issues Arduino users face, especially on Windows 10 and 11. The good news is it’s usually easy to fix once you understand what’s causing it.

In this guide, we’ll explain why your Arduino isn’t being detected, and walk you through step-by-step fixes to make the port appear again and get your board working properly.

Why Is Arduino Port Not Showing Up?

If your Arduino’s port isn’t visible in the IDE or Device Manager, there are several possible causes. Let’s go through the most common ones:

  1. Faulty USB cable or port – Some USB cables are for charging only, not for data transfer.
  2. Missing or outdated USB drivers – The CH340 or FTDI drivers might not be installed.
  3. Incorrect or loose connection – The board might not be seated properly in the port.
  4. Power issues – Insufficient power through USB can cause detection failure.
  5. Corrupted Arduino IDE settings – Sometimes, IDE preferences or cache cause connection issues.
  6. Damaged Arduino board – Hardware faults or a burned USB-to-serial chip can prevent detection.
  7. Windows driver conflicts – Windows may be using a generic driver instead of the correct one.

Now, let’s fix it step-by-step.

Fix Arduino Port Not Showing Up or Not Detected on Windows 11

Follow these solutions one by one until your Arduino is successfully detected by your PC.

1. Check the USB Cable and Port

Before diving into software fixes, start with the basics.

  • Make sure your USB cable supports data transfer, not just charging.
  • Try using another cable that you know works with data (for example, your phone-to-PC cable).
  • Plug the Arduino into a different USB port on your computer — preferably a USB 2.0 port instead of 3.0.
  • If you’re using a USB hub, connect the board directly to your PC instead.

After plugging it in, open Device Manager and check under Ports (COM & LPT). If your board still isn’t visible, continue below.

2. Restart Your Computer

It sounds too simple, but restarting can reset driver communication issues.

  1. Save your work and close all programs.
  2. Press Alt + F4 and choose Restart.
  3. After rebooting, reconnect your Arduino board and check if the COM port appears.

If not, move to the next step.

3. Install or Update Arduino USB Drivers

Each Arduino model uses a different USB-to-serial chip. You need the correct driver for it to be detected.

For Official Arduino Boards (UNO, Mega, Nano Original)

  1. Open Device Manager → look for Other devices → you might see “Unknown device.”
  2. Right-click it → choose Update driver → Browse my computer for drivers.
  3. Navigate to: C:\Program Files (x86)\Arduino\drivers
  4. Select that folder and click Next to install.

For Clone Boards (CH340 or FTDI Chips)

Many low-cost Arduino clones use the CH340 or FT232R FTDI chip. You’ll need to install their drivers manually.

After installation, reconnect your board and check if a new COM port appears in Device Manager.

4. Manually Assign a COM Port

Sometimes, Windows installs the driver correctly but doesn’t assign a port number.

  1. Press Windows + X → choose Device Manager.
  2. Expand Ports (COM & LPT).
  3. Right-click your Arduino device → Properties → Port Settings → Advanced.
  4. Under COM Port Number, select a different unused port (like COM3 or COM4).
  5. Click OK and restart the Arduino IDE.

Now, go to Tools > Port and check if your Arduino port shows up.

5. Reinstall the Arduino IDE

Sometimes, the IDE itself fails to recognize ports due to outdated settings or installation issues.
To fix this:

  1. Uninstall the Arduino IDE from your PC.
  2. Go to Arduino’s official site and download the latest version.
  3. Install it as an administrator (right-click → Run as administrator).
  4. Plug in your Arduino and check if the Port option under Tools becomes active.

6. Disable Driver Signature Enforcement (For CH340 Boards)

Some third-party drivers like CH340 aren’t digitally signed, which Windows 11 may block.

You can temporarily disable this restriction to install them:

  1. Press Shift + Restart to enter Advanced Startup.
  2. Go to Troubleshoot → Advanced options → Startup Settings → Restart.
  3. When options appear, press 7 (Disable driver signature enforcement).
  4. Once Windows boots, install the CH340 driver manually again.

After installation, reboot normally and check if your Arduino port appears.

7. Try a Different USB Controller Mode

Some newer laptops have USB selective suspend or power management settings that can disable USB ports temporarily.

  1. Press Windows + X → Device Manager.
  2. Expand Universal Serial Bus controllers.
  3. Right-click each USB Root Hub (USB 3.0) entry → Properties.
  4. Under Power Management, uncheck: Allow the computer to turn off this device to save power
  5. Click OK, reconnect your Arduino, and check for detection.

8. Check Arduino Board Connection & Reset Button

Sometimes the issue isn’t with the port — it’s the board itself.

  • Make sure the board’s ON LED lights up when connected.
  • Try pressing the RESET button once after connecting.
  • If you have multiple Arduino boards, test another one on the same cable and PC.

If other boards work fine, your current Arduino may have a faulty USB-to-serial chip.

9. Use Zadig Tool (for Advanced Users)

If Windows assigns a generic USB driver that Arduino IDE can’t recognize, you can reinstall the correct one using Zadig:

  1. Download Zadig from zadig.akeo.ie.
  2. Run it as administrator.
  3. From the list, choose your Arduino device (like CH340 or USB Serial).
  4. Choose WinUSB or USB Serial (CDC) from the driver dropdown.
  5. Click Install Driver.

After that, restart the IDE and check if the COM port appears.

10. Try a Different Computer

If nothing works, connect your Arduino to another PC or laptop. If it shows up there, the problem lies with your Windows drivers or USB controller — not the board.

If it still doesn’t appear on another computer, it’s likely that the Arduino’s USB interface chip is damaged.

Final Words

The Arduino Port Not Showing Up issue can be frustrating — especially when you’re eager to upload your first sketch. But as we’ve seen, it’s usually caused by something simple like a bad cable, missing driver, or Windows configuration issue.

Start with basic checks like using a different cable or port, and work your way up through driver installation and COM port reassignment.

Once your Arduino board is properly detected, it’ll appear under Tools > Port in the IDE — and you’ll be ready to upload and run your projects again!

Arpita

With a background in Computer Science, she is passionate about sharing practical programming tips and tech know-how. From writing clean code to solving everyday tech problems, she breaks down complex topics into approachable guides that help others learn and grow.