Arduino “not recognized” – How to troubleshoot it?

I was so excited to get my hands on my first Arduino that ended up buying a fake version that my PC could not even recognize. So, I had to learn How to troubleshoot a “not recognized” Arduino. Here’s what I learned.

If your Arduino is “not recognized,” How to troubleshoot it? You can troubleshoot Arduino by following these steps:

  1. Installing the right drivers
  2. Updating the drivers
  3. Replacing the faulty chip
  4. Getting a new connecting cable
  5. Repairing your USB slot

Troubleshooting “not recognized” Arduino can be a bit of a daunting task since these errors can pop up for several reasons I explain below so you can get rid of the “not recognized” error and finally start with your project.

What Is the Arduino “Not Recognized” Error?

The Arduino “not recognized” error is one of the most common types of errors faced by its users. Whether you’re a beginner or an advanced programmer, you will or may have encountered this error at least once.

Typically what happens is, when you plug in your Arduino’s USB cable into your PC’s USB port, you can see which Arduino board is connected through one of the COM ports (e.g., COM4, COM6, etc.) in the Arduino IDE.

You can check this in your PC by clicking on the “Tools” tab in the Arduino IDE and then hovering over the “Port” tab. You’ll see one of the COM ports mentioned along with the name of your Arduino board like shown below.

Arduino recognized on COM6 Port.

This indicates that your Arduino board has been successfully recognized by your PC, and you can start uploading your code in it.

Additionally, when you open the IDE, a sentence on the lower right side appears, which indicates that your Arduino board is connected on one of the COM ports, for example, “Arduino UNO on COM7”.

On the other hand, if your PC fails to recognize your board, you won’t see the name of your Arduino board written on the lower right corner of the IDE, and neither would you find it in the “Ports” section, under the “Tools” tab.

Another way to check if your Arduino board has been recognized is through the device manager. In case the Arduino board has not been identified, you’ll find it in the Device Manager under the “Other Devices” tab with the name of the USB port (for example, USB2.0-Serial).

On the contrary, if the Arduino is recognized, you will find it with its name in the Device Manager area.

Why Is My Computer Not Recognizing My Arduino Board?

There can be several reasons why your computer has failed to recognize the Arduino board.

These are the 5 most common reason why your computer isn’t recognizing your Arduino:

Reason #1: Your Arduino Board is Fake

There are many fake Arduino boards available in the market, which cost about one fifth the price of the original one (including shipping charges).

Still, the downside of buying these boards is that most of the time, they’re not recognized by your computer.

What’s the reason? Well, as these boards are not original, they’re not accompanied by the original drivers which are installed on your computer when you plug in the board. Hence, the PC/laptop fails to recognize these cheap Arduino boards.

Reason #2: Counterfeit Serial to USB Chip

Usually, Arduino boards come with an FTDI chip, which helps them to communicate with the PC/laptop. This chip is called a serial to USB chip, which means that it serves as a gateway between the Arduino board and your computer.

Your Arduino might look like it is original, but it’s possible that the FTDI chip mounted on it is counterfeit, which is why your computer is not recognizing it.

Reason #3: Arduino Board Not Working

It might be possible that you have a genuine Arduino board with the right type of serial to USB chip and the proper drivers installed, but your Arduino may be damaged or has a fried/faulty serial to a USB chip.

Having any of these problems means that your Arduino will not be able to send or receive signals to/from your PC; therefore, your computer fails to recognize the faulty Arduino board.

Reason #4: Problems with the USB Slot

Have you checked your PC/laptop’s USB slot that you are using to connect the Arduino? Is the USB slot working correctly? It might be possible that your computer’s USB slot is the culprit behind this problem.

Similarly, the USB 2.0 connector cable might be at fault.

If you’re living with pets inside your house, the chances are that they might have chewed on your connector cable, and that is why your Arduino board is not recognized by your PC because it is simply not connected.

In this case, your Arduino board would not turn on, and you won’t see the usual LED blinking on the board, which, under normal circumstances, blinks when the Arduino board is powered on.

Reason #5: Outdated Drivers

If you have an original Arduino board with the right serial to USB chip and there are no problems with the USB cable or the USB slot, then the last thing at fault could be the driver.

When an Arduino board is connected to a computer, it automatically identifies itself and installs the relevant drivers, which are necessary for the two-way communication between the two devices.

Sometimes, despite everything falling into place, the drivers installed are outdated. To solve this problem, you will have to make a manual installation, which we will cover in the next section.

So, How to Fix This “Not Recognized” Error?

Fixing the error is easy once you know why the error is present in the first place.

After going through all of the possibilities mentioned in the previous section, now you must be sure why your computer is not recognizing the Arduino board.

Here are the solutions for all the errors mentioned above. We are sure that you will find the solution for your case under one of these headings.

Solution #1: Installing the Right Driver

In case you have a fake Arduino or an Arduino with a counterfeit chip, you need to install the right driver to solve your problem.


If you scrutinize your Arduino board, you will notice that there is a CH340G chip embedded on the board.

All you need to do is download the driver for CH340G and install it.

After successful installation, try connecting your Arduino board to your computer. You will notice that it has been recognized. You can check it through the Arduino IDE or via the Windows device manager.

Solution #2: Updating the Driver

If your driver is outdated, then you need to update it.

For that, you need to connect the Arduino board with your PC/laptop and then open the device manager and look for the unrecognized USB port under the “Other Devices” tab.

Then, right-click on the unrecognized USB port and click on “Update Driver Software.”

This will launch the Update Driver Software manager for your Arduino board, and upon successful completion, your computer would be able to recognize the Arduino board.

If not, then unplug the Arduino board from the USB port and reconnect it to your computer.

Solution #3: Replacing the Faulty Chip

In case your Arduino board has a fried or a faulty USB to serial chip/ATmega328 microcontroller chip, then you need to replace it by buying a new one.

If you’re not sure how to replace the chip, you can follow this video tutorial on YouTube. Even if your counterfeit board looks different, the procedure is the same. Do it carefully and using the proper tools, as shown in the video.

After replacing the chip, connect the Arduino board to your computer and check if it has been recognized by either opening the Arduino IDE or visiting the device manager.

If the problem persists, follow the steps mentioned below.

Solution #4: Getting a New Connecting Cable

Your connecting cable may be faulty, and the best way to know that is by observing the mini LED that blinks when you power on your Arduino board. When the LED lights up, that means your connecting cable is OK.

If not, try ordering a new USB 2.0 cable type A/B for our Arduino. If the problem persists, then you need to check your computer’s USB slot.

Solution #5: Repairing Your USB Slot

If you have connected your Arduino board with the computer using a new USB 2.0 cable and the mini LED still doesn’t light up, then you need to check your computer’s USB slot.

Try connecting some other device on the same USB slot and check whether your computer recognizes it or not. If not, that means your Arduino board is OK, and the culprit is your computer’s USB slot.

If you have tried all of the above and your Arduino board is still not being recognized by your PC, then you must consider replacing your existing board with a new one.

Final thoughts

By now, you must have found out what the problem with your Arduino board is and how to troubleshoot it.

Arduino is one of the most-commonly used microcontroller boards all around the world, and errors like these are faced by people now and then.

You will find plenty of articles on the internet that can walk your way through many common Arduino-related problems.

Dig in deeper on my site, and you’ll land on excellent articles that can solve your problem! I am active and adding more almost every day.

What problems have you encountered while developing your Arduino projects? Let us know in the comments, and let’s find a solution for it!


Engineer and electronics enthusiast. Enjoys solving problems with electronics and programming.

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