Fix: COM Ports Not Showing in Device Manager

Issue: COM Ports Not Showing in Device Manager

You may be mystified when you open Device Manager and the "Ports (COM & LPT)" section is missing or lists no serial ports. You might experience this problem after updating the Windows OS, having a misconfigured BIOS, or driver corruption.

Symptoms of the issue:

• Serial devices are not detected on a COM port
• A USB-to-serial adapter is not recognized or is malfunctioning
• Device Manager displays no COM ports on the system

Who’s affected by COM ports not showing up?

• Technicians working with networking hardware or serial devices
• Software developers who use serial interfaces like Raspberry Pi or Arduino
• Industrial equipment operators

Don’t worry, we'll show you how to find COM ports that seem to have disappeared.

You have added virtual serial ports that any Windows application can use.

NOTE: If users require multiple ports for testing or debugging, the software supports port pairs and advanced configurations, including loopbacks and shared ports.

Pros:
• Fixes some issues where Device Manager shows no COM ports
• No hardware requirements
• Emulates physical serial communication

Cons:
• Does not address BIOS or driver issues
• A paid solution with a free trial available

Manual Troubleshooting Solutions

Simple system issues are often the cause of COM ports not appearing in Device Manager on Windows 10 systems. Users can usually resolve issues such as faulty hardware settings, hidden devices, and missing drivers using native operating system tools.

This section shows you how to check COM ports and recover and enable them without the need for additional software. These techniques can help you restore access to the COM ports on your Windows computer.

Run the Hardware Troubleshooter

Best for inexperienced users or when you have no idea what is causing the problem.

Windows provides a built-in Hardware and Devices troubleshooter that can detect and fix common system issues. It’s a quick process that may help resolve missing or invisible COM ports.

Use Windows Troubleshooter to Detect and Fix COM Port Problems

1. Press Win + I > Update & Security > Troubleshoot.
2. Click “Additional troubleshooters”.
3. Select Hardware and Devices and run the troubleshooter.
   
   

Pros:
• A user-friendly and automated solution
• Resolves common issues with missing components

Cons:
• Provides limited diagnostic information
• Does not address advanced or virtual use cases

Enable Hidden Devices in Device Manager

Best used when previously installed COM ports are not visible in Device Manager.

Windows may hide disconnected or idle COM ports, making them invisible to Device Manager. Once they are enabled, the OS will display the ports. Enabling ports is a fast and straightforward method of seeing if existing COM ports are not visible.

How to Show Hidden COM Ports in Device Manager

1. Press Win + X to Open Device Manager.
2. Click View > Show hidden devices.
3. Expand the Ports (COM & LPT) section.
4. Right-click and enable or uninstall and reinstall any hidden ports.
   
   

Pros:
• Fast and simple
• No third-party tools required

Cons:
• Will not address missing issues with ports or drivers

Install or Update Serial Drivers

Best when users have updated Windows or introduced new hardware to the system.

One of the most common reasons Device Manager does not display COM ports is that the serial port drivers are missing, obsolete, or corrupt. Users can restore lost functionality and communication with serial devices by installing or updating the drivers.

How to Install or Update Serial Port Drivers in Windows 10

1. Open Device Manager.
2. Right-click the root of your PC name and select “Scan for hardware changes”.
3. If ports appear, right-click and select “Update driver”.
4. You can also download drivers directly from the device manufacturer’s site.
   
   

Pros:
• Improves system stability and security
• Can restore missing ports quickly

Cons:
• Requires some technical knowledge regarding your hardware
• Windows Update may not provide the most effective

Add a Legacy COM port

Best suited for IT users who need to add ports on legacy systems or virtual machines.

You can manually add a virtual entry for a COM port using the “Add Legacy Hardware” wizard in Device Manager when the OS does not automatically detect the port. This procedure creates a serial port profile for legacy devices requiring driver support or manual port recognition.

Add a Missing COM Port Manually via Legacy Hardware

1. Open Device Manager.
2. Go to Action > Add legacy hardware.
3. Click Next > Install the hardware that I manually select.
4. Scroll to Ports (COM & LPT) > Standard port types.
5. Complete the wizard with the appropriate information to create a new COM port.
   
   

Pros:
• Can be used in virtual environments
• Effective when auto-detection fails

Cons:
• May not indicate physical port status
• Provides limited control over port configuration

Check BIOS/UEFI Settings

Best for users with computers equipped with physical COM ports.

Physical COM ports may be disabled by default in the BIOS or UEFI firmware settings to conserve resources. If you are certain the hardware exists but the COM ports are not visible in Device Manager, enabling the port through the BIOS may resolve the issue.

The process reactivates serial interfaces at the hardware level, allowing the operating system to detect them and assign port numbers during startup. It resolves issues wth built-in COM ports that must be activated in firmware to be visible to the OS.

How to Enable a COM Port in BIOS or UEFI

1. Restart your computer and enter the BIOS/UEFI, typically by pressing the Del, F2, or Esc keys at startup.
2. Look for settings labeled "Serial Port," "COM Port," or "Super I/O Configuration".
3. Enable the desired ports and save your changes.
   
   

Pros:
• Permanently fixes disabled hardware
• Necessary for physical port activation

Cons:
• BIOS interfaces may be challenging to navigate
• Misconfiguration can occur and cause further issues

Check Serial Ports Using CMD or PowerShell

Best suited for system administrators, developers, or users looking for a quick, command-line diagnostic solution.

You may need to know how to find which COM ports are currently active. You can utilize built-in Windows command-line tools to obtain this information, which offer a scriptable solution for enhanced productivity.

How to Check Active COM Ports via PowerShell and CMD

PowerShell

1. Open PowerShell as an administrator.
2. Run the following command:
   Get-WmiObject Win32_SerialPort
3. The output will provide details on all active COM ports, including their name, status, and device IDs.
   
   

CMD method

1. Open the Windows Command Prompt as an administrator.
2. Run the simple command: mode
3. Look for listed COM ports.
   
   

Pros:
• Works when no COM ports are visible in Device Manager
• Fast and scriptable solution
• No additional software required

Cons:
• Provides limited debugging data with no live monitoring
• Only displays configured and active serial ports

How to Troubleshoot USB-to-COM Adapters

Best used when working with USB-to-serial adapters and legacy serial devices.

Many users employ USB-to-COM adapters to emulate serial ports on computers without physical COM ports. The adapters require special drivers. If the drivers are improperly installed, the adapter may not be visible in Device Manager.

Fixing USB-to-Serial Adapters not Visible in Device Manager

1. Connect the USB-to-COM adapter to your computer..
2. Open Device Manager → Expand Ports (COM & LPT).
3. If the adapter is not visible, follow these steps:
4. Check for an unrecognized device under Universal Serial Bus controllers.
5. Right-click and choose Update Driver. You can also download and install the manufacturer’s driver.
   
   

After installing or updating the driver, note the adapter’s assigned COM port.

Pros:
• Typically, a plug-and-play solution is available after the driver is installed or updated
• Provides a straightforward method for connecting legacy hardware to modern systems that lack serial ports

Cons:
• Inexpensive adapters may produce driver issues
• Not all adapters are compatible with Windows 10
• Unusual COM port numbers may be assigned, which can affect software compatibility

Our advanced solutions can help identify issues with COM port visibility and facilitate reliable communication with serial devices.

You can find additional information about COM port configuration and troubleshooting at the following links:

Conclusion

COM port visibility is essential when working with legacy devices or serial software applications. You can restore visibility with the simple methods described above.

The most efficient method of addressing the problem of COM ports not displaying in Device Manager is to install the Virtual Serial Port Driver utility. The tool emulates physical serial ports with virtual interfaces for modern PCs without COM ports. The software also helps users diagnose COM port issues that impact their productivity.